Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2018	Jul. 26, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q2
Trading Symbol	NVR
Entity Registrant Name	NVR INC
Entity Central Index Key	0000906163
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		3,627,049

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Inventory:
Land under development	$ 35,292
Contract land deposits, net	361,052	$ 370,429
Total assets	3,009,395	2,989,279
LIABILITIES AND SHAREHOLDERS' EQUITY
Total liabilities	1,401,824	1,383,787
Commitments and contingencies
Shareholders' equity:
Common stock, $0.01 par value; 60,000,000 shares authorized; 20,555,330 shares issued as of both June 30, 2018 and December 31, 2017	206	206
Additional paid-in capital	1,721,696	1,644,197
Deferred compensation trust – 107,904 and 108,640 shares of NVR, Inc. common stock as of June 30, 2018 and December 31, 2017, respectively	(17,148)	(17,383)
Deferred compensation liability	17,148	17,383
Retained earnings	6,603,359	6,231,940
Less treasury stock at cost – 16,926,815 and 16,864,324 shares as of June 30, 2018 and December 31, 2017, respectively	(6,717,690)	(6,270,851)
Total shareholders' equity	1,607,571	1,605,492
Total liabilities and shareholders' equity	3,009,395	2,989,279
Homebuilding [Member]
ASSETS
Cash and cash equivalents	417,341	645,087
Restricted cash	22,130	19,438
Receivables	30,179	20,026
Inventory:
Lots and housing units, covered under sales agreements with customers	1,263,408	1,046,094
Unsold lots and housing units	113,493	148,620
Land under development	35,292	34,212
Building materials and other	21,422	17,273
Total Inventory	1,433,615	1,246,199
Contract land deposits, net	361,052	370,429
Property, plant and equipment, net	41,612	43,191
Reorganization value in excess of amounts allocable to identifiable assets, net	41,580	41,580
Other assets	205,760	198,930
Total assets	2,553,269	2,584,880
LIABILITIES AND SHAREHOLDERS' EQUITY
Accounts payable	290,923	261,973
Accrued expenses and other liabilities	306,452	341,891
Customer deposits	172,033	150,033
Senior notes	597,373	597,066
Total liabilities	1,366,781	1,350,963
Mortgage Banking [Member]
ASSETS
Cash and cash equivalents	14,209	21,707
Restricted cash	3,672	2,256
Mortgage loans held for sale, net	399,806	352,489
Inventory:
Property, plant and equipment, net	7,018	6,327
Reorganization value in excess of amounts allocable to identifiable assets, net	7,347	7,347
Other assets	24,074	14,273
Total assets	456,126	404,399
LIABILITIES AND SHAREHOLDERS' EQUITY
Accounts payable and other liabilities	35,043	32,824
Total liabilities	$ 35,043	$ 32,824

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common stock, par value (USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	20,555,330	20,555,330
Deferred compensation trust, shares	107,904	108,640
Treasury stock, shares	16,926,815	16,864,324

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest expense	$ (6,329)	$ (5,914)	$ (12,611)	$ (11,750)
Income before taxes	241,586	208,968	432,584	341,129
Income tax expense	(38,412)	(61,091)	(63,361)	(90,329)
Net income	$ 203,174	$ 147,877	$ 369,223	$ 250,800
Basic earnings per share (USD per share)	$ 55.90	$ 39.46	$ 101.03	$ 67.30
Diluted earnings per share (USD per share)	$ 49.05	$ 35.19	$ 88.31	$ 60.36
Basic weighted average shares outstanding (in shares)	3,635	3,748	3,655	3,726
Diluted weighted average shares outstanding (in shares)	4,142	4,202	4,181	4,155
Homebuilding [Member]
Revenues	$ 1,750,463	$ 1,512,714	$ 3,240,556	$ 2,760,301
Other income	2,164	1,447	4,141	2,549
Cost of sales	(1,416,797)	(1,218,083)	(2,628,743)	(2,244,100)
Selling, general and administrative	(106,517)	(99,100)	(212,064)	(199,004)
Operating income	229,313	196,978	403,890	319,746
Interest expense	(6,047)	(5,641)	(12,054)	(11,219)
Income before taxes	223,266	191,337	391,836	308,527
Mortgage Banking [Member]
Mortgage banking fees	36,842	31,778	76,163	61,283
Interest income	2,915	1,554	5,008	3,215
Other income	641	506	1,165	815
General and administrative	(21,796)	(15,934)	(41,031)	(32,180)
Interest expense	(282)	(273)	(557)	(531)
Income before taxes	$ 18,320	$ 17,631	$ 40,748	$ 32,602

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income	$ 369,223	$ 250,800
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,024	11,494
Equity-based compensation expense	28,104	21,467
Contract land deposit impairments, net	44	3,567
Gain on sale of loans, net	(58,891)	(47,474)
Mortgage loans closed	(2,223,302)	(1,772,432)
Mortgage loans sold and principal payments on mortgage loans held for sale	2,229,894	1,936,118
Distribution of earnings from unconsolidated joint ventures	2,849	2,643
Net change in assets and liabilities:
Increase in inventory	(187,416)	(272,851)
Decrease in contract land deposits	9,333	17,872
Increase in receivables	(10,417)	(1,674)
Decrease in accounts payable and accrued expenses	(11,332)	(3,013)
Increase in customer deposits	22,000	43,448
Other, net	(10,663)	(11,757)
Net cash provided by operating activities	169,450	178,208
Cash flows from investing activities:
Investments in and advances to unconsolidated joint ventures	(284)	(455)
Distribution of capital from unconsolidated joint ventures	6,027	5,238
Purchase of property, plant and equipment	(9,251)	(9,784)
Proceeds from the sale of property, plant and equipment	425	472
Net cash used in investing activities	(3,083)	(4,529)
Cash flows from financing activities:
Purchase of treasury stock	(483,538)	(159,506)
Proceeds from the exercise of stock options	86,094	117,966
Net cash used in financing activities	(397,444)	(41,540)
Net (decrease) increase in cash, restricted cash, and cash equivalents	(231,077)	132,139
Cash, restricted cash, and cash equivalents, beginning of the period	689,557	416,037
Cash, restricted cash, and cash equivalents, end of the period	458,480	548,176
Supplemental disclosures of cash flow information:
Interest paid during the period, net of interest capitalized	12,151	11,293
Income taxes paid during the period, net of refunds	$ 86,269	$ 99,370

Basis of Presentation	6 Months Ended
Basis of Presentation	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited, condensed consolidated financial statements include the accounts of NVR, Inc. (“NVR” or the “Company”) and its subsidiaries and certain other entities in which the Company is deemed to be the primary beneficiary (see Notes 2 and 3 to the accompanying condensed consolidated financial statements). Intercompany accounts and transactions have been eliminated in consolidation. The statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. Because the accompanying condensed consolidated financial statements do not include all of the information and footnotes required by GAAP, they should be read in conjunction with the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. In the opinion of management, all adjustments (consisting only of normal recurring accruals except as otherwise noted herein) considered necessary for a fair presentation have been included. Operating results for the three and six months ended June 30, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Certain prior period amounts in the condensed consolidated statements of cash flows have been reclassified to conform to current period presentation. These reclassifications did not impact total cash from operating, investing or financing activities in the statement of cash flows. For the three and six months ended June 30, 2018 and 2017, comprehensive income equaled net income; therefore, a separate statement of comprehensive income is not included in the accompanying condensed consolidated financial statements. Recently Adopted Accounting Pronouncements Revenue from Contracts with Customers On January 1, 2018, the Company adopted Accounting Standards Update 2014-09, Revenue from Contracts with Customers (Topic 606), using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Revenue Recognition Consistent with the Company’s previous revenue recognition practice, homebuilding revenue is recognized on the settlement date at the contract sales price, when control is transferred to our customers. Mortgage banking revenue recognition will continue to be governed by Accounting Standards Codification ("ASC") Topic 815 - Derivatives and Hedging and by ASC Topic 825 - Financial Instruments, and is not subject to Topic 606. See Note 10 for disclosure of revenue by reporting segment. The Company’s contract liabilities, consisting of deposits received from customers (“Handmoney”) on homes not settled, were $172,033 and $167,486 as of June 30, 2018 and March 31, 2018, respectively. During the second quarter of 2018, the Company recognized in revenue approximately $90,000 of the Handmoney held as of March 31, 2018. The Company’s prepaid sales compensation totaled approximately $20,100 and $19,500, as of June 30, 2018 and December 31, 2017, respectively. These amounts are included in homebuilding “Other assets” on the accompanying condensed consolidated balance sheets. Deferred Revenue Topic 606 no longer requires sellers of real estate to consider the initial and continuing involvement criteria in ASC 360-20, but instead only conclude on the collectibility of the transaction price. On January 1, 2018, the Company recorded a cumulative-effect adjustment, net of tax, of $2,196 to recognize deferred profit on home settlements, which the Company had previously determined that there was significant continuing involvement and believed to be fully collectible. Practical Expedients and Exemption At contract inception, the performance obligation to complete and settle the home with a customer has an expected duration of less than one year. As a result, the Company does not disclose the value of unsatisfied performance obligations for contracts. No other adjustments were made as a result of the adoption of Topic 606. Other recently adopted accounting pronouncements The Company adopted ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments, effective January 1, 2018. In connection with the adoption of ASU 2016-15, the Company made the election to classify distributions received from unconsolidated joint ventures using the cumulative earnings approach. This election was applied retrospectively, which reclassified a portion of distributions received from the Company's unconsolidated joint ventures between operating and investing activities on the prior year condensed consolidated statement of cash flows. The adoption of this standard did not have a material effect on the Company's condensed consolidated statements of cash flows and related disclosures. The Company adopted ASU 2016-18, Statement of Cash Flows (Topic 230), Restricted Cash, effective January 1, 2018. The amendments in the standard require that the statement of cash flows explain the change during the period in the total of cash, cash equivalents and restricted cash or restricted cash equivalents. As a result, the Company's beginning-of-period and end-of-period cash balances presented in the condensed consolidated statements of cash flows were retrospectively adjusted to include restricted cash with cash and cash equivalents. The Company's cash and cash equivalents include short-term investments with original maturities of three months or less. Homebuilding restricted cash was attributable to customer deposits for certain home sales. Mortgage banking restricted cash included amounts collected from customers for loans in process and closed mortgage loans held for sale. The beginning-of-period and end-of-period cash, restricted cash, and cash equivalent balances presented on the accompanying condensed consolidated statements of cash flows include cash related to a consolidated joint venture, which is included in homebuilding "Other assets" on the Company's condensed consolidated balance sheets. The cash related to this consolidated joint venture as of June 30, 2018 and December 31, 2017 was $1,128 and $1,069, respectively, and as of June 30, 2017 and December 31, 2016 was $1,199 and $1,214, respectively. The adoption of this standard did not have a material effect on the Company's condensed consolidated statements of cash flows and related disclosures. The Company also adopted ASU 2017-09, Compensation – Stock Compensation (Topic 718), Scope of Modification Accounting, effective January 1, 2018. The amendments in the standard clarify when changes in a share-based payment award must be accounted for as a modification, and will allow entities to make certain changes to share-based payment awards without accounting for them as modifications. Under the new guidance, entities will only apply modification accounting if there are substantive changes made to share-based payment awards. If a change made to a share-based payment award does not affect the fair value, vesting conditions and classification as either an equity or liability instrument, modification accounting will not need to be applied. The adoption of this standard did not have any effect on the Company's condensed consolidated financial statements and related disclosures.

Variable Interest Entities ("VIEs")

6 Months Ended

Jun. 30, 2018

Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure [Abstract]

Variable Interest Entities

Variable Interest Entities ("VIEs")

Fixed Price Finished Lot Purchase Agreements (“Lot Purchase Agreements”)

NVR generally does not engage in the land development business. Instead, the Company typically acquires finished building lots at market prices from various development entities under Lot Purchase Agreements. The Lot Purchase Agreements require deposits that may be forfeited if NVR fails to perform under the Lot Purchase Agreements. The deposits required under the Lot Purchase Agreements are in the form of cash or letters of credit in varying amounts, and typically range up to 10% of the aggregate purchase price of the finished lots.

NVR believes this lot acquisition strategy reduces the financial requirements and risks associated with direct land ownership and land development. NVR may, at its option, choose for any reason and at any time not to perform under these Lot Purchase Agreements by delivering notice of its intent not to acquire the finished lots under contract. NVR’s sole legal obligation and economic loss for failure to perform under these Lot Purchase Agreements is limited to the amount of the deposit pursuant to the liquidated damage provisions contained within the Lot Purchase Agreements. None of the creditors of any of the development entities with which NVR enters Lot Purchase Agreements have recourse to the general credit of NVR. NVR generally does not have any specific performance obligations to purchase a certain number or any of the lots, nor does NVR guarantee completion of the development by the developer or guarantee any of the developers’ financial or other liabilities.

NVR is not involved in the design or creation of the development entities from which the Company purchases lots under Lot Purchase Agreements. The developer’s equity holders have the power to direct 100% of the operating activities of the development entity. NVR has no voting rights in any of the development entities. The sole purpose of the development entity’s activities is to generate positive cash flow returns for the equity holders. Further, NVR does not share in any of the profit or loss generated by the project’s development. The profits and losses are passed directly to the developer’s equity holders.

The deposit placed by NVR pursuant to the Lot Purchase Agreement is deemed to be a variable interest in the respective development entities. Those development entities are deemed to be VIEs. Therefore, the development entities with which NVR enters into Lot Purchase Agreements, including the joint venture limited liability corporations discussed below, are evaluated for possible consolidation by NVR. An enterprise must consolidate a VIE when that enterprise has a controlling financial interest in the VIE. An enterprise is deemed to have a controlling financial interest if it has (i) the power to direct the activities of a VIE that most significantly impact the entity’s economic performance, and (ii) the obligation to absorb losses of the VIE that could be significant to the VIE or the rights to receive benefits from the VIE that could be significant to the VIE.

NVR believes the activities that most significantly impact a development entity’s economic performance are the operating activities of the entity. The development entity’s equity investors bear the full risk during the development process. Unless and until a development entity completes finished building lots through the development process, the entity does not earn any revenues. The operating development activities are managed solely by the development entity’s equity investors.

The development entities with which NVR contracts to buy finished lots typically select the respective projects, obtain the necessary zoning approvals, obtain the financing required with no support or guarantees from NVR, select who will purchase the finished lots and at what price, and manage the completion of the infrastructure improvements, all for the purpose of generating a cash flow return to the development entity’s equity holders and all independent of NVR. The Company possesses no more than limited protective legal rights through the Lot Purchase Agreement in the specific finished lots that it is purchasing, and NVR possesses no participative rights in the development entities. Accordingly, NVR does not have the power to direct the activities of a developer that most significantly impact the developer’s economic performance. For this reason, NVR has concluded that it is not the primary beneficiary of the development entities with which the Company enters into Lot Purchase Agreements, and therefore, NVR does not consolidate any of these VIEs.

As of June 30, 2018, NVR controlled approximately 90,100 lots under Lot Purchase Agreements with third parties through deposits in cash and letters of credit totaling approximately $377,400 and $2,700, respectively. As noted above, NVR’s sole legal obligation and economic loss for failure to perform under these Lot Purchase Agreements is limited to the amount of the deposit pursuant to the liquidated damage provisions contained in the Lot Purchase Agreements.

In addition, NVR has certain properties under contract with land owners that are expected to yield approximately 9,900 lots, which are not included in the number of total lots controlled. Some of these properties may require rezoning or other approvals to achieve the expected yield. These properties are controlled with deposits in cash and letters of credit totaling approximately $10,900 and $100, respectively, as of June 30, 2018, of which approximately $2,100 is refundable if certain contractual conditions are not met. NVR generally expects to assign the raw land contracts to a land developer and simultaneously enter into a Lot Purchase Agreement with the assignee if the project is determined to be feasible.

NVR’s total risk of loss related to contract land deposits as of June 30, 2018 and December 31, 2017 was as follows:



	June 30, 2018			December 31, 2017
Contract land deposits	$	388,331		$	400,428
Loss reserve on contract land deposits	(27,279		)	(29,999		)
Contract land deposits, net	361,052			370,429
Contingent obligations in the form of letters of credit	2,798			1,996
Specific performance obligations (1)	1,505			1,505
Total risk of loss	$	365,355		$	373,930


(1)	As of both June 30, 2018 and December 31, 2017, the Company was committed to purchase 10 finished lots under specific performance obligations.

Joint Ventures

6 Months Ended

Jun. 30, 2018

Equity Method Investments and Joint Ventures [Abstract]

Joint Ventures

On a limited basis, NVR obtains finished lots using joint venture limited liability corporations (“JVs”). The JVs are typically structured such that NVR is a non-controlling member and is at risk only for the amount the Company has invested, or has committed to invest, in addition to any deposits placed under Lot Purchase Agreements with the joint venture. NVR is not a borrower, guarantor or obligor on any debt of the JVs, as applicable. The Company enters into Lot Purchase Agreements to purchase lots from these JVs, and as a result has a variable interest in these JVs.

At June 30, 2018, the Company had an aggregate investment totaling approximately $40,000 in six JVs that are expected to produce approximately 7,000 finished lots, of which approximately 3,650 lots were controlled by the Company and the remaining approximately 3,350 lots were either under contract with unrelated parties or not currently under contract. In addition, NVR had additional funding commitments totaling approximately $5,000 in the aggregate to three of the JVs at June 30, 2018. The Company has determined that it is not the primary beneficiary of five of the JVs because either NVR and the other JV partner share power or the other JV partner has the controlling financial interest. The aggregate investment in unconsolidated JVs was approximately $39,700 and $49,000 at June 30, 2018 and December 31, 2017, respectively, and is reported in the “Other assets” line item on the accompanying condensed consolidated balance sheets. For the remaining JV, NVR has concluded that it is the primary beneficiary because the Company has the controlling financial interest in the JV.

The condensed balance sheets as of June 30, 2018 and December 31, 2017 of the consolidated JV were as follows:



	June 30, 2018		December 31, 2017
Assets:
Cash	$	1,128	$	1,069
Other assets	37		37
Total assets	$	1,165	$	1,106

Liabilities and equity:
Accrued expenses	$	484	$	487
Equity	681		619
Total liabilities and equity	$	1,165	$	1,106

The Company recognizes income from the JVs as a reduction to the lot cost of the lots purchased from the respective JVs when the homes are settled, based on the expected total profitability and the total number of lots expected to be produced by the respective JVs. With the Company's adoption of ASU 2016-15 effective January 1, 2018, the Company made the election to classify distributions received from unconsolidated JVs using the cumulative earnings approach. As a result, distributions received up to the amount of cumulative earnings recognized by the Company are reported as distributions of earnings and those in excess of that amount are reported as a distribution of capital. These distributions are classified within the accompanying condensed consolidated statements of cash flows as cash flows from operating activities and investing activities, respectively. See Note 1 for additional discussion regarding the Company's adoption of ASU 2016-15.

Land Under Development	6 Months Ended
Land Under Development	Jun. 30, 2018
Real Estate [Abstract]
Land Under Development	Land Under Development On a limited basis, NVR directly acquires raw land parcels already zoned for its intended use to develop into finished lots. Land under development includes the land acquisition costs, direct improvement costs, capitalized interest where applicable, and real estate taxes. As of June 30, 2018, NVR directly owned a total of four separate raw land parcels with a carrying value of $35,292 that are expected to produce approximately 450 finished lots. The Company also has additional funding commitments of approximately $8,300 under a joint development agreement related to one parcel, a portion of which the Company expects will be offset by development credits of approximately $4,800. None of the raw parcels had any indicators of impairment as of June 30, 2018.

Capitalized Interest

6 Months Ended

Jun. 30, 2018

Capitalized Interest Costs, Including Allowance for Funds Used During Construction [Abstract]

Capitalized Interest

The Company capitalizes interest costs to land under development during the active development of finished lots. In addition, the Company capitalizes interest costs to its joint venture investments while the investments are considered qualified assets pursuant to ASC Topic 835-20 - Interest. Capitalized interest is transferred to sold or unsold inventory as the development of finished lots is completed, then charged to cost of sales upon the Company’s settlement of homes and the respective lots. Interest incurred in excess of the interest capitalizable based on the level of qualified assets is expensed in the period incurred.

The following table reflects the changes in the Company's capitalized interest during the three and six months ended June 30, 2018 and 2017:



	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Interest capitalized, beginning of period	$	5,545		$	5,564		$	5,583		$	5,106
Interest incurred	6,624			6,580			13,220			13,139
Interest charged to interest expense	(6,329		)	(5,914		)	(12,611		)	(11,750		)
Interest charged to cost of sales	(452		)	(278		)	(804		)	(543		)
Interest capitalized, end of period	$	5,388		$	5,952		$	5,388		$	5,952

Earnings per Share

6 Months Ended

Jun. 30, 2018

Earnings Per Share [Abstract]

Earnings per Share

The following weighted average shares and share equivalents were used to calculate basic and diluted earnings per share for the three and six months ended June 30, 2018 and 2017:



	Three Months Ended June 30,		Six Months Ended June 30,
	2018	2017	2018	2017
Weighted average number of shares outstanding used to calculate basic EPS	3,635	3,748	3,655	3,726
Dilutive securities:
Stock options and restricted share units	507	454	526	429
Weighted average number of shares and share equivalents outstanding used to calculate diluted EPS	4,142	4,202	4,181	4,155

The following non-qualified stock options ("Options") issued under equity incentive plans were outstanding during the three and six months ended June 30, 2018 and 2017, but were not included in the computation of diluted earnings per share because the effect would have been anti-dilutive.



	Three Months Ended June 30,		Six Months Ended June 30,
	2018	2017	2018	2017
Anti-dilutive securities	349	9	349	15

Equity-Based Compensation

6 Months Ended

Jun. 30, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Equity-Based Compensation

The Company’s shareholders approved the NVR, Inc. 2018 Equity Incentive Plan (the "2018 Plan") at the Company’s Annual Meeting of Shareholders held on May 2, 2018. The 2018 Plan authorizes the Company to issue Options and restricted share units ("RSUs") to key management employees, including executive officers and members of our Board of Directors ("Directors"), to acquire up to an aggregate 275 shares of the Company’s common stock. Of the 275 aggregate shares available to issue, all may be granted in the form of Options and up to 40 may be granted in the form of RSUs.

During the second quarter of 2018, the Company issued 332 Options and 16 RSUs under the NVR, Inc. 2010 Equity Incentive Plan (the "2010 Plan"), the NVR, Inc. 2014 Equity Incentive Plan (the "2014 Plan"), and the 2018 Plan as follows:



	2010 Plan	2014 Plan	2018 Plan
Options Granted
Options - service-only (1)	4	90	72
Options - performance-based (2)	—	94	72
Total Options Granted	4	184	144

RSUs Granted
RSUs - service-only (3)	8	—	—
RSUs - performance-based (4)	8	—	—
Total RSUs Granted	16	—	—

(1) Of the 166 service-only Options granted, 34 will vest over two years in 50% increments on December 31, 2020 and 2021; the remaining 132 Options will vest over four years in 25% increments on December 31, 2020, 2021, 2022, and 2023. Vesting for the Options is contingent solely upon continued employment or continued service as a Director.

(2) Of the 166 performance-based Options granted, 34 will vest over two years in 50% increments on December 31, 2020 and 2021; the remaining 132 performance-based Options will vest over four years in 25% increments on December 31, 2020, 2021, 2022, and 2023. Vesting for the performance-based Options is contingent upon both continued employment or continued service as a Director and the Company's return on capital performance during 2018 through 2020.

(3) The service-only RSUs granted will vest over two years in 50% increments on December 31, 2022 and 2023. Vesting for the RSUs is contingent solely upon continued employment.

(4) The performance-based RSUs granted will vest over two years in 50% increments on December 31, 2022 and 2023. Vesting for the performance-based RSUs is contingent upon both continued employment and the Company's return on capital performance during 2018 through 2020.

In addition to the above equity grant, the Company also issued 8 Options under the 2014 Plan during the six months ended June 30, 2018. The Options granted will vest annually over four years in 25% increments beginning on December 31, 2020. Vesting for 50% of the Options granted is contingent upon both continued employment and the Company's return on capital performance during 2018 through 2020, while vesting for the other 50% of the Options granted is contingent solely upon continued employment.

All Options were granted at an exercise price equal to the closing price of the Company’s common stock on the day prior to the date of grant, and expire ten years from the date of grant.

The following table provides additional information relative to NVR's equity-based compensation plans for the six months ended June 30, 2018:



Options	Shares		Weighted Average Per Share Exercise Price
Outstanding at December 31, 2017	916		$	1,119.92
Granted	340		3,023.76
Exercised	(91	)	949.64
Forfeited	(27	)	1,300.09
Outstanding at June 30, 2018	1,138		$	1,697.50
Exercisable at June 30, 2018	371		$	959.65

RSUs
Outstanding at December 31, 2017	10
Granted	16
Vested	(5	)
Forfeited	—
Outstanding at June 30, 2018	21
Vested, but not issued at June 30, 2018	—

To estimate the grant-date fair value of its Options, the Company uses the Black-Scholes option-pricing model (the “Pricing Model”). The Pricing Model estimates the per share fair value of an option on its date of grant based on the following factors: the option’s exercise price, the price of the underlying stock on the date of grant, the estimated dividend yield, a risk-free interest rate, the estimated option term, and the expected volatility. For the risk-free interest rate, the Company uses U.S. Treasury STRIPS which mature at approximately the same time as the option’s expected holding term. For expected volatility, NVR has concluded that its historical volatility over the option’s expected holding term provides the most reasonable basis for this estimate.

The fair value of the Options granted during 2018 was estimated on the grant date using the Pricing Model, based on the following assumptions:



		2018
Estimated option life (years)		5.06
Risk-free interest rate (range)		2.19% - 2.99%
Expected volatility (range)		16.57% - 18.83%
Expected dividend rate		—%
Weighted average grant date fair value per share of Options granted		$689.47

The grant date fair value per share of $3,022.99 for the RSUs granted during 2018 was the closing price of the Company's common stock on the day immediately preceding the grant date.

Compensation cost for Options and RSUs is recognized on a straight-line basis over the requisite service period for the entire award (from the date of grant through the period of the last separately vesting portion of the grant). For the recognition of equity-based compensation, the Options and RSUs that are subject to a performance condition are treated as a separate award from the “service-only” Options and RSUs, and compensation expense for Options and RSUs subject to a performance condition is recognized when it becomes probable that the stated performance target will be achieved. The Company currently believes that it is probable that the performance condition will be satisfied at the target level and is recognizing compensation expense related to such Options and RSUs accordingly. Compensation cost is recognized within the income statement in the same expense line as the cash compensation paid to the respective employees.

The Company recognizes forfeitures of equity-based awards as a reduction to compensation costs in the period in which they occur. Total equity-based compensation expense recognized during the three and six months ended June 30, 2018 was $18,595 and $28,104, respectively. During the three and six months ended June 30, 2017, total equity-based compensation expense recognized was $10,878 and $21,467, respectively.

As of June 30, 2018, the total unrecognized compensation cost for all outstanding Options and RSUs was approximately $347,900. The unrecognized compensation cost will be recognized over each grant’s applicable vesting period, with the latest vesting date being December 31, 2023. Unrecognized compensation costs may change depending on the satisfaction of the performance-based metric, discussed above. The weighted-average period over which the unrecognized compensation will be recorded is equal to approximately 2.8 years.

Shareholders' Equity

6 Months Ended

Jun. 30, 2018

Equity [Abstract]

Shareholders' Equity

Shareholders’ Equity

A summary of changes in shareholders’ equity is presented below:



	Common Stock		Additional Paid-In Capital			Retained Earnings		Treasury Stock			Deferred Compensation Trust			Deferred Compensation Liability			Total
Balance, December 31, 2017	$	206	$	1,644,197		$	6,231,940	$	(6,270,851	)	$	(17,383	)	$	17,383		$	1,605,492

Cumulative-effect adjustment from adoption of ASU 2014-09, net of tax	—		—			2,196		—			—			—			2,196
Net income	—		—			369,223		—			—			—			369,223
Deferred compensation activity, net	—		—			—		—			235			(235		)	—
Purchase of common stock for treasury	—		—			—		(483,538		)	—			—			(483,538		)
Equity-based compensation	—		28,104			—		—			—			—			28,104
Proceeds from Options exercised	—		86,094			—		—			—			—			86,094
Treasury stock issued upon option exercise and restricted share vesting	—		(36,699		)	—		36,699			—			—			—
Balance, June 30, 2018	$	206	$	1,721,696		$	6,603,359	$	(6,717,690	)	$	(17,148	)	$	17,148		$	1,607,571

The Company repurchased approximately 158 shares of its common stock during the six months ended June 30, 2018. The Company settles Option exercises and vesting of RSUs by issuing shares of treasury stock. Approximately 96 shares were issued from the treasury account during the six months ended June 30, 2018 in settlement of Option exercises and vesting of RSUs. Shares are relieved from the treasury account based on the weighted average cost basis of treasury shares acquired.

Product Warranties

6 Months Ended

Jun. 30, 2018

Product Warranties Disclosures [Abstract]

Product Warranties

The Company establishes warranty and product liability reserves (“Warranty Reserve”) to provide for estimated future expenses as a result of construction and product defects, product recalls and litigation incidental to NVR’s homebuilding business. Liability estimates are determined based on management’s judgment, considering such factors as historical experience, the estimated current cost of corrective action, manufacturers’ and subcontractors’ participation in sharing the cost of corrective action, consultations with third party experts such as engineers, and discussions with the Company’s general counsel and outside counsel retained to handle specific product liability cases.

The following table reflects the changes in the Company’s Warranty Reserve during the three and six months ended June 30, 2018 and 2017:



	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Warranty reserve, beginning of period	$	95,606		$	93,503		$	94,513		$	93,895
Provision	16,217			13,206			27,744			22,167
Payments	(12,121		)	(11,315		)	(22,555		)	(20,668		)
Warranty reserve, end of period	$	99,702		$	95,394		$	99,702		$	95,394

Segment Disclosures

6 Months Ended

Jun. 30, 2018

Segment Reporting [Abstract]

Segment Disclosures

The following disclosure includes four homebuilding reportable segments that aggregate geographically the Company’s homebuilding operating segments, and the mortgage banking operations presented as one reportable segment. The homebuilding reportable segments are comprised of operating divisions in the following geographic areas:



Mid Atlantic:		Maryland, Virginia, West Virginia, Delaware and Washington, D.C.
North East:		New Jersey and Eastern Pennsylvania
Mid East:		New York, Ohio, Western Pennsylvania, Indiana and Illinois
South East:		North Carolina, South Carolina, Florida and Tennessee

Homebuilding profit before tax includes all revenues and income generated from the sale of homes, less the cost of homes sold, selling, general and administrative expenses and a corporate capital allocation charge. The corporate capital allocation charge is eliminated in consolidation and is based on the segment’s average net assets employed. The corporate capital allocation charged to the operating segment allows the Chief Operating Decision Maker (“CODM”) to determine whether the operating segment’s results are providing the desired rate of return after covering the Company’s cost of capital.

Certain assets are not allocated to the operating segments as those assets are neither included in the operating segment’s corporate capital allocation charge, nor in the CODM’s evaluation of the operating segment’s performance. The Company records charges on contract land deposits when it is determined that it is probable that recovery of the deposit is impaired. For segment reporting purposes, impairments on contract land deposits are generally charged to the operating segment upon the termination of a Lot Purchase Agreement with the developer, or the restructuring of a Lot Purchase Agreement resulting in the forfeiture of the deposit. Mortgage banking profit before tax consists of revenues generated from mortgage financing, title insurance and closing services, less the costs of such services and general and administrative costs. Mortgage banking operations are not charged a corporate capital allocation charge.

In addition to the corporate capital allocation and contract land deposit impairments discussed above, the other reconciling items between segment profit and consolidated profit before tax include unallocated corporate overhead (including all management incentive compensation), equity-based compensation expense, consolidation adjustments and external corporate interest expense. NVR’s overhead functions, such as accounting, treasury and human resources, are centrally performed and the costs are not allocated to the Company’s operating segments. Consolidation adjustments consist of such items necessary to convert the reportable segments’ results, which are predominantly maintained on a cash basis, to a full accrual basis for external financial statement presentation purposes, and are not allocated to the Company’s operating segments. External corporate interest expense primarily consists of interest charges on the Company’s 3.95% Senior Notes due 2022 (the “Senior Notes”) and is not charged to the operating segments because the charges are included in the corporate capital allocation discussed above.

The following tables present segment revenues, profit and assets with reconciliations to the amounts reported for the consolidated enterprise, where applicable:



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Revenues:
Homebuilding Mid Atlantic	$	973,677	$	872,148	$	1,816,173	$	1,594,416
Homebuilding North East	147,618		127,541		270,332		233,771
Homebuilding Mid East	363,288		313,237		653,525		556,268
Homebuilding South East	265,880		199,788		500,526		375,846
Mortgage Banking	36,842		31,778		76,163		61,283
Total consolidated revenues	$	1,787,305	$	1,544,492	$	3,316,719	$	2,821,584



	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Income before taxes:
Homebuilding Mid Atlantic	$	112,221		$	100,621		$	203,268		$	165,109
Homebuilding North East	16,777			14,112			32,481			23,218
Homebuilding Mid East	42,174			35,986			69,385			58,145
Homebuilding South East	29,203			22,911			52,440			37,481
Mortgage Banking	19,685			18,004			42,235			33,957
Total segment profit before taxes	220,060			191,634			399,809			317,910
Reconciling items:
Contract land deposit reserve adjustment (1)	592			(2,064		)	2,720			(2,792		)
Equity-based compensation expense (2)	(18,595		)	(10,878		)	(28,104		)	(21,467		)
Corporate capital allocation (3)	53,954			49,646			104,653			95,833
Unallocated corporate overhead	(22,503		)	(23,360		)	(53,787		)	(50,594		)
Consolidation adjustments and other	14,109			9,614			19,311			13,427
Corporate interest expense	(6,031		)	(5,624		)	(12,018		)	(11,188		)
Reconciling items sub-total	21,526			17,334			32,775			23,219
Consolidated income before taxes	$	241,586		$	208,968		$	432,584		$	341,129


(1)	This item represents changes to the contract land deposit impairment reserve, which are not allocated to the reportable segments.


(2)	The increase in equity-based compensation expense in the three and six month periods ended June 30, 2018 was primarily attributable to the issuance of Options and RSUs in the second quarter of 2018. See Note 7 for additional discussion of equity-based compensation.


(3)	This item represents the elimination of the corporate capital allocation charge included in the respective homebuilding reportable segments. The corporate capital allocation charge is based on the segment’s monthly average asset balance, and was as follows for the periods presented:



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Corporate capital allocation charge:
Homebuilding Mid Atlantic	$	31,501	$	31,005	$	61,949	$	60,130
Homebuilding North East	4,580		4,133		8,760		7,947
Homebuilding Mid East	9,057		7,535		17,030		14,277
Homebuilding South East	8,816		6,973		16,914		13,479
Total	$	53,954	$	49,646	$	104,653	$	95,833



	June 30, 2018			December 31, 2017
Assets:
Homebuilding Mid Atlantic	$	1,139,958		$	1,079,225
Homebuilding North East	155,089			143,008
Homebuilding Mid East	322,718			263,019
Homebuilding South East	315,599			277,705
Mortgage Banking	448,779			397,052
Total segment assets	2,382,143			2,160,009
Reconciling items:
Cash and cash equivalents	417,341			645,087
Deferred taxes	116,295			111,953
Intangible assets and goodwill	50,066			50,144
Contract land deposit reserve	(27,279		)	(29,999		)
Consolidation adjustments and other	70,829			52,085
Reconciling items sub-total	627,252			829,270
Consolidated assets	$	3,009,395		$	2,989,279

Fair Value

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Fair Value

GAAP assigns a fair value hierarchy to the inputs used to measure fair value. Level 1 inputs are quoted prices in active markets for identical assets and liabilities. Level 2 inputs are inputs other than quoted market prices that are observable for the asset or liability, either directly or indirectly. Level 3 inputs are unobservable inputs.

Financial Instruments

The estimated fair value of NVR’s Senior Notes was $630,000 as of both June 30, 2018 and December 31, 2017. The estimated fair value is based on recent market prices of similar transactions, which is classified as Level 2 within the fair value hierarchy. The carrying values at June 30, 2018 and December 31, 2017 were $597,373 and $597,066, respectively. Except as otherwise noted below, NVR believes that insignificant differences exist between the carrying value and the fair value of its financial instruments, which consist primarily of cash equivalents, due to their short term nature.

Derivative Instruments and Mortgage Loans Held for Sale

In the normal course of business, NVR’s wholly-owned mortgage subsidiary, NVR Mortgage Finance, Inc. (“NVRM”), enters into contractual commitments to extend credit to NVR’s homebuyers with fixed expiration dates. The commitments become effective when the borrowers "lock-in" a specified interest rate within time frames established by NVRM. All mortgagors are evaluated for credit worthiness prior to the extension of the commitment. Market risk arises if interest rates move adversely between the time of the "lock-in" of rates by the borrower and the sale date of the loan to a broker/dealer. To mitigate the effect of the interest rate risk inherent in providing rate lock commitments to borrowers, NVRM enters into optional or mandatory delivery forward sale contracts to sell whole loans and mortgage-backed securities to broker/dealers. The forward sales contracts lock in an interest rate and price for the sale of loans similar to the specific rate lock commitments. NVRM does not engage in speculative or trading derivative activities. Both the rate lock commitments to borrowers and the forward sale contracts to broker/dealers are undesignated derivatives and, accordingly, are marked to fair value through earnings. At June 30, 2018, there were contractual commitments to extend credit to borrowers aggregating $857,052 and open forward delivery contracts aggregating $1,168,371, which hedge both the rate lock loan commitments and closed loans held for sale.

The fair value of NVRM’s rate lock commitments to borrowers and the related input levels include, as applicable:


i)	the assumed gain/loss of the expected resultant loan sale (Level 2);


ii)	the effects of interest rate movements between the date of the rate lock and the balance sheet date (Level 2); and


iii)	the value of the servicing rights associated with the loan (Level 2).

The assumed gain/loss considers the excess servicing to be received or buydown fees to be paid upon securitization of the loan. The excess servicing and buydown fees are calculated pursuant to contractual terms with investors. To calculate the effects of interest rate movements, NVRM utilizes applicable published mortgage-backed security prices, and multiplies the price movement between the rate lock date and the balance sheet date by the notional loan commitment amount. NVRM sells all of its loans on a servicing released basis, and receives a servicing released premium upon sale. Thus, the value of the servicing rights is included in the fair value measurement and is based upon contractual terms with investors and varies depending on the loan type. NVRM assumes a fallout rate when measuring the fair value of rate lock commitments. Fallout is defined as locked loan commitments for which NVRM does not close a mortgage loan and is based on historical experience.

The fair value of NVRM’s forward sales contracts to broker/dealers solely considers the market price movement of the same type of security between the trade date and the balance sheet date (Level 2). The market price changes are multiplied by the notional amount of the forward sales contracts to measure the fair value.

Mortgage loans held for sale are recorded at fair value when closed, and thereafter are carried at the lower of cost or fair value, net of deferred origination costs, until sold. Fair value is measured using Level 2 inputs. The fair value of loans held for sale of $399,806 included on the accompanying condensed consolidated balance sheet has been increased by $6,548 from the aggregate principal balance of $393,258. As of December 31, 2017, the fair value of loans held for sale of $352,489 were increased by $1,931 from the aggregate principal balance of $350,558.

The fair value measurement of NVRM's undesignated derivative instruments was as follows:




	June 30, 2018			December 31, 2017
Rate lock commitments:
Gross assets	$	13,770		$	5,400
Gross liabilities	996			1,832
Net rate lock commitments	$	12,774		$	3,568
Forward sales contracts:
Gross assets	$	408		$	992
Gross liabilities	4,307			667
Net forward sales contracts	$	(3,899	)	$	325

As of June 30, 2018, the net rate lock commitments are reported in mortgage banking "Other assets" and the net forward sales contracts are reported in mortgage banking "Accrued expenses and other liabilities" on the accompanying condensed consolidated balance sheets. As of December 31, 2017, both the net rate lock commitments and the net forward sales contracts are reported in mortgage banking "Other assets".

The fair value measurement as of June 30, 2018 was as follows:



	Notional or Principal Amount		Assumed Gain/(Loss) From Loan Sale		Interest Rate Movement Effect		Servicing Rights Value		Security Price Change			Total Fair Value Measurement Gain/(Loss)
Rate lock commitments	$	857,052	$	1,402	$	1,683	$	9,689	$	—		$	12,774
Forward sales contracts	$	1,168,371	—		—		—		(3,899		)	(3,899		)
Mortgages held for sale	$	393,258	881		376		5,291		—			6,548
Total fair value measurement			$	2,283	$	2,059	$	14,980	$	(3,899	)	$	15,423

The total fair value measurement as of December 31, 2017 was $5,824. For the three and six months ended June 30, 2018, NVRM recorded a fair value adjustment to income of $5,585 and $9,599, respectively. For the three and six months ended June 30, 2017, NVRM recorded a fair value adjustment to income of $3,376 and $1,359, respectively. Unrealized gains/losses from the change in the fair value measurements are included in earnings as a component of mortgage banking fees in the accompanying condensed consolidated statements of income. The fair value measurement will be impacted in the future by the change in the value of the servicing rights, interest rate movements, security price fluctuations, and the volume and product mix of NVRM’s closed loans and locked loan commitments.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Debt	6 Months Ended
Debt	Jun. 30, 2018
Debt Disclosure [Abstract]
Debt	Debt Senior Notes As of June 30, 2018, the Company had Senior Notes outstanding with a principal balance of $600,000. The Senior Notes mature on September 15, 2022 and bear interest at 3.95%, payable semi-annually in arrears on March 15 and September 15. The Senior Notes were issued at a discount to yield 3.97% and have been reflected net of the unamortized discount and unamortized debt issuance costs in the accompanying condensed consolidated balance sheet. Credit Agreement NVR has an unsecured Credit Agreement (the “Credit Agreement”), which provides for aggregate revolving loan commitments of $200,000 (the “Facility”). Under the Credit Agreement, the Company may request increases of up to $300,000 to the Facility in the form of revolving loan commitments or term loans to the extent that new or existing lenders agree to provide additional revolving loan or term loan commitments. The Credit Agreement provides for a $100,000 sublimit for the issuance of letters of credit, of which approximately $8,500 was outstanding at June 30, 2018, and a $25,000 sublimit for a swing line commitment. The Credit Agreement termination date is July 15, 2021. There was no debt outstanding under the Facility at June 30, 2018. Repurchase Agreement NVRM provides for its mortgage origination and other operating activities using cash generated from its operations, borrowings from its parent company, NVR, as well as a revolving mortgage repurchase agreement (the “Repurchase Agreement”), which is non-recourse to NVR. The Repurchase Agreement provides for loan purchases up to $150,000, subject to certain sub-limits. Amounts outstanding under the Repurchase Agreement are collateralized by the Company’s mortgage loans held for sale. In July 2018, NVRM entered into the Tenth Amendment (the "Amendment") to its Repurchase Agreement, filed herewith as Exhibit 10.1. The Amendment removed the $50,000 incremental commitment that was available under the prior Repurchase Agreement. All other terms and conditions under the Repurchase Agreement remained materially consistent. The Repurchase Agreement expires on July 24, 2019. At June 30, 2018, there were no borrowing base limitations reducing the amount available under the Repurchase Agreement. There was no debt outstanding under the Repurchase Agreement at June 30, 2018.

Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company and its subsidiaries are involved in various litigation arising in the ordinary course of business. In the opinion of management, and based on advice of legal counsel, this litigation is not expected to have a material adverse effect on the financial position, results of operations or cash flows of the Company. Legal costs incurred in connection with outstanding litigation are expensed as incurred.

Income Taxes

6 Months Ended

Jun. 30, 2018

Income Tax Disclosure [Abstract]

Income Taxes

The Company’s effective tax rate for the three and six months ended June 30, 2018 was 15.9% and 14.6%, respectively. For the three and six months ended June 30, 2017, the Company's effective tax rate was 29.2% and 26.5%, respectively. The reduction in the effective tax rate was primarily due to the following items:


•	The enactment of the Tax Cuts and Jobs Act in December 2017, which lowered the Company's federal statutory tax rate from 35% to 21%, and


•	The retroactive reinstatement of certain expired energy tax credits under the Bipartisan Budget Act of 2018, which resulted in the Company recognizing a tax benefit of approximately $6,200 in the first quarter of 2018 related to homes settled in 2017.

Additionally, the effective tax rate for the three and six months ended June 30, 2018 and 2017 was favorably impacted by the recognition of an income tax benefit related to excess tax benefits from stock option exercises. This income tax benefit was $26,456 and $46,022 for the three and six months ended June 30, 2018, respectively, and was $16,464 and $36,364 for the three and six months ended June 30, 2017, respectively.

Recent Accounting Pronouncements	6 Months Ended
Recent Accounting Pronouncements	Jun. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (the "FASB") issued ASU 2016-02, Leases (Topic 842), which requires lessees to recognize most leases on-balance sheet with a liability equal to the present value of lease payments over the lease term and a right-of-use asset for the right to use the underlying asset over the lease term. Lessees will recognize expenses on their income statements in a manner similar to current GAAP. The standard also requires additional disclosures of key information about leasing arrangements. The standard is effective for the Company as of January 1, 2019. Based on its current portfolio of leases, the Company believes that adoption of this standard will result in the recognition of less than $100,000 of right-of-use assets and corresponding liabilities on its balance sheet, predominately related to real estate leases. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326), which significantly changes the way impairment of financial assets is recognized. The standard will require immediate recognition of estimated credit losses expected to occur over the remaining life of many financial assets, which will generally result in earlier recognition of allowances for credit losses on loans and other financial instruments. The standard’s provisions will be applied as a cumulative-effect adjustment to beginning retained earnings as of the effective date. The standard is effective for the Company as of January 1, 2020. Early adoption is permitted for annual and interim periods beginning January 1, 2019. The Company does not believe that the adoption of this standard will have a material effect on its consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment. The standard’s objective is to simplify the subsequent measurement of goodwill by eliminating the second step from the goodwill impairment test. Under the amendments in the standard, an entity would perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. If the carrying amount of a reporting unit exceeds its fair value, an impairment charge would then be recognized, not to exceed the amount of goodwill allocated to that reporting unit. The standard is effective for the Company on January 1, 2020, and early adoption is permitted. The Company does not believe that the adoption of this standard will have a material effect on its consolidated financial statements and related disclosures.

Basis of Presentation (Policies)	6 Months Ended
Basis of Presentation (Policies)	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
New Accounting Pronouncements	Recently Adopted Accounting Pronouncements Revenue from Contracts with Customers On January 1, 2018, the Company adopted Accounting Standards Update 2014-09, Revenue from Contracts with Customers (Topic 606), using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Revenue Recognition Consistent with the Company’s previous revenue recognition practice, homebuilding revenue is recognized on the settlement date at the contract sales price, when control is transferred to our customers. Mortgage banking revenue recognition will continue to be governed by Accounting Standards Codification ("ASC") Topic 815 - Derivatives and Hedging and by ASC Topic 825 - Financial Instruments, and is not subject to Topic 606. See Note 10 for disclosure of revenue by reporting segment. The Company’s contract liabilities, consisting of deposits received from customers (“Handmoney”) on homes not settled, were $172,033 and $167,486 as of June 30, 2018 and March 31, 2018, respectively. During the second quarter of 2018, the Company recognized in revenue approximately $90,000 of the Handmoney held as of March 31, 2018. The Company’s prepaid sales compensation totaled approximately $20,100 and $19,500, as of June 30, 2018 and December 31, 2017, respectively. These amounts are included in homebuilding “Other assets” on the accompanying condensed consolidated balance sheets. Deferred Revenue Topic 606 no longer requires sellers of real estate to consider the initial and continuing involvement criteria in ASC 360-20, but instead only conclude on the collectibility of the transaction price. On January 1, 2018, the Company recorded a cumulative-effect adjustment, net of tax, of $2,196 to recognize deferred profit on home settlements, which the Company had previously determined that there was significant continuing involvement and believed to be fully collectible. Practical Expedients and Exemption At contract inception, the performance obligation to complete and settle the home with a customer has an expected duration of less than one year. As a result, the Company does not disclose the value of unsatisfied performance obligations for contracts. No other adjustments were made as a result of the adoption of Topic 606. Other recently adopted accounting pronouncements The Company adopted ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments, effective January 1, 2018. In connection with the adoption of ASU 2016-15, the Company made the election to classify distributions received from unconsolidated joint ventures using the cumulative earnings approach. This election was applied retrospectively, which reclassified a portion of distributions received from the Company's unconsolidated joint ventures between operating and investing activities on the prior year condensed consolidated statement of cash flows. The adoption of this standard did not have a material effect on the Company's condensed consolidated statements of cash flows and related disclosures. The Company adopted ASU 2016-18, Statement of Cash Flows (Topic 230), Restricted Cash, effective January 1, 2018. The amendments in the standard require that the statement of cash flows explain the change during the period in the total of cash, cash equivalents and restricted cash or restricted cash equivalents. As a result, the Company's beginning-of-period and end-of-period cash balances presented in the condensed consolidated statements of cash flows were retrospectively adjusted to include restricted cash with cash and cash equivalents. The Company's cash and cash equivalents include short-term investments with original maturities of three months or less. Homebuilding restricted cash was attributable to customer deposits for certain home sales. Mortgage banking restricted cash included amounts collected from customers for loans in process and closed mortgage loans held for sale. The beginning-of-period and end-of-period cash, restricted cash, and cash equivalent balances presented on the accompanying condensed consolidated statements of cash flows include cash related to a consolidated joint venture, which is included in homebuilding "Other assets" on the Company's condensed consolidated balance sheets. The cash related to this consolidated joint venture as of June 30, 2018 and December 31, 2017 was $1,128 and $1,069, respectively, and as of June 30, 2017 and December 31, 2016 was $1,199 and $1,214, respectively. The adoption of this standard did not have a material effect on the Company's condensed consolidated statements of cash flows and related disclosures. The Company also adopted ASU 2017-09, Compensation – Stock Compensation (Topic 718), Scope of Modification Accounting, effective January 1, 2018. The amendments in the standard clarify when changes in a share-based payment award must be accounted for as a modification, and will allow entities to make certain changes to share-based payment awards without accounting for them as modifications. Under the new guidance, entities will only apply modification accounting if there are substantive changes made to share-based payment awards. If a change made to a share-based payment award does not affect the fair value, vesting conditions and classification as either an equity or liability instrument, modification accounting will not need to be applied. The adoption of this standard did not have any effect on the Company's condensed consolidated financial statements and related disclosures. Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (the "FASB") issued ASU 2016-02, Leases (Topic 842), which requires lessees to recognize most leases on-balance sheet with a liability equal to the present value of lease payments over the lease term and a right-of-use asset for the right to use the underlying asset over the lease term. Lessees will recognize expenses on their income statements in a manner similar to current GAAP. The standard also requires additional disclosures of key information about leasing arrangements. The standard is effective for the Company as of January 1, 2019. Based on its current portfolio of leases, the Company believes that adoption of this standard will result in the recognition of less than $100,000 of right-of-use assets and corresponding liabilities on its balance sheet, predominately related to real estate leases. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326), which significantly changes the way impairment of financial assets is recognized. The standard will require immediate recognition of estimated credit losses expected to occur over the remaining life of many financial assets, which will generally result in earlier recognition of allowances for credit losses on loans and other financial instruments. The standard’s provisions will be applied as a cumulative-effect adjustment to beginning retained earnings as of the effective date. The standard is effective for the Company as of January 1, 2020. Early adoption is permitted for annual and interim periods beginning January 1, 2019. The Company does not believe that the adoption of this standard will have a material effect on its consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment. The standard’s objective is to simplify the subsequent measurement of goodwill by eliminating the second step from the goodwill impairment test. Under the amendments in the standard, an entity would perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. If the carrying amount of a reporting unit exceeds its fair value, an impairment charge would then be recognized, not to exceed the amount of goodwill allocated to that reporting unit. The standard is effective for the Company on January 1, 2020, and early adoption is permitted. The Company does not believe that the adoption of this standard will have a material effect on its consolidated financial statements and related disclosures.

Variable Interest Entities ("VIEs") (Tables)

6 Months Ended

Jun. 30, 2018

Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure [Abstract]

Total Risk of Loss Related to Contract Land Deposits

NVR’s total risk of loss related to contract land deposits as of June 30, 2018 and December 31, 2017 was as follows:



	June 30, 2018			December 31, 2017
Contract land deposits	$	388,331		$	400,428
Loss reserve on contract land deposits	(27,279		)	(29,999		)
Contract land deposits, net	361,052			370,429
Contingent obligations in the form of letters of credit	2,798			1,996
Specific performance obligations (1)	1,505			1,505
Total risk of loss	$	365,355		$	373,930


(1)	As of both June 30, 2018 and December 31, 2017, the Company was committed to purchase 10 finished lots under specific performance obligations.

- Definition

Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.

+ References + Details

Joint Ventures (Tables)

6 Months Ended

Jun. 30, 2018

Consolidated Joint Venture [Member]

Schedule of Equity Method Investments [Line Items]

Condensed Balance Sheets

The condensed balance sheets as of June 30, 2018 and December 31, 2017 of the consolidated JV were as follows:



	June 30, 2018		December 31, 2017
Assets:
Cash	$	1,128	$	1,069
Other assets	37		37
Total assets	$	1,165	$	1,106

Liabilities and equity:
Accrued expenses	$	484	$	487
Equity	681		619
Total liabilities and equity	$	1,165	$	1,106

Capitalized Interest (Tables)

6 Months Ended

Jun. 30, 2018

Capitalized Interest Costs, Including Allowance for Funds Used During Construction [Abstract]

Summary of Interest Costs Incurred, Capitalized, Expensed and Charged to Cost of Sales

The following table reflects the changes in the Company's capitalized interest during the three and six months ended June 30, 2018 and 2017:



	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Interest capitalized, beginning of period	$	5,545		$	5,564		$	5,583		$	5,106
Interest incurred	6,624			6,580			13,220			13,139
Interest charged to interest expense	(6,329		)	(5,914		)	(12,611		)	(11,750		)
Interest charged to cost of sales	(452		)	(278		)	(804		)	(543		)
Interest capitalized, end of period	$	5,388		$	5,952		$	5,388		$	5,952

Earnings per Share (Tables)

6 Months Ended

Jun. 30, 2018

Earnings Per Share [Abstract]

Weighted Average Shares and Share Equivalents Used to Calculate Basic and Diluted Earnings Per Share

The following weighted average shares and share equivalents were used to calculate basic and diluted earnings per share for the three and six months ended June 30, 2018 and 2017:



	Three Months Ended June 30,		Six Months Ended June 30,
	2018	2017	2018	2017
Weighted average number of shares outstanding used to calculate basic EPS	3,635	3,748	3,655	3,726
Dilutive securities:
Stock options and restricted share units	507	454	526	429
Weighted average number of shares and share equivalents outstanding used to calculate diluted EPS	4,142	4,202	4,181	4,155

Summary of Antidilutive Securities Excluded from Computation of Earnings Per Share



	Three Months Ended June 30,		Six Months Ended June 30,
	2018	2017	2018	2017
Anti-dilutive securities	349	9	349	15

Equity-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Equity-Based Compensation Plans with Grants Outstanding



	2010 Plan	2014 Plan	2018 Plan
Options Granted
Options - service-only (1)	4	90	72
Options - performance-based (2)	—	94	72
Total Options Granted	4	184	144

RSUs Granted
RSUs - service-only (3)	8	—	—
RSUs - performance-based (4)	8	—	—
Total RSUs Granted	16	—	—

(3) The service-only RSUs granted will vest over two years in 50% increments on December 31, 2022 and 2023. Vesting for the RSUs is contingent solely upon continued employment.

Equity-Based Compensations Plans

The following table provides additional information relative to NVR's equity-based compensation plans for the six months ended June 30, 2018:



Options	Shares		Weighted Average Per Share Exercise Price
Outstanding at December 31, 2017	916		$	1,119.92
Granted	340		3,023.76
Exercised	(91	)	949.64
Forfeited	(27	)	1,300.09
Outstanding at June 30, 2018	1,138		$	1,697.50
Exercisable at June 30, 2018	371		$	959.65

RSUs
Outstanding at December 31, 2017	10
Granted	16
Vested	(5	)
Forfeited	—
Outstanding at June 30, 2018	21
Vested, but not issued at June 30, 2018	—

Black-Scholes Option-Pricing Model Assumptions

The fair value of the Options granted during 2018 was estimated on the grant date using the Pricing Model, based on the following assumptions:



		2018
Estimated option life (years)		5.06
Risk-free interest rate (range)		2.19% - 2.99%
Expected volatility (range)		16.57% - 18.83%
Expected dividend rate		—%
Weighted average grant date fair value per share of Options granted		$689.47

Shareholders' Equity (Tables)

6 Months Ended

Jun. 30, 2018

Equity [Abstract]

Summary of Changes in Shareholders' Equity

A summary of changes in shareholders’ equity is presented below:



	Common Stock		Additional Paid-In Capital			Retained Earnings		Treasury Stock			Deferred Compensation Trust			Deferred Compensation Liability			Total
Balance, December 31, 2017	$	206	$	1,644,197		$	6,231,940	$	(6,270,851	)	$	(17,383	)	$	17,383		$	1,605,492

Cumulative-effect adjustment from adoption of ASU 2014-09, net of tax	—		—			2,196		—			—			—			2,196
Net income	—		—			369,223		—			—			—			369,223
Deferred compensation activity, net	—		—			—		—			235			(235		)	—
Purchase of common stock for treasury	—		—			—		(483,538		)	—			—			(483,538		)
Equity-based compensation	—		28,104			—		—			—			—			28,104
Proceeds from Options exercised	—		86,094			—		—			—			—			86,094
Treasury stock issued upon option exercise and restricted share vesting	—		(36,699		)	—		36,699			—			—			—
Balance, June 30, 2018	$	206	$	1,721,696		$	6,603,359	$	(6,717,690	)	$	(17,148	)	$	17,148		$	1,607,571

Product Warranties (Tables)

6 Months Ended

Jun. 30, 2018

Product Warranties Disclosures [Abstract]

Summary of Changes in Product Warranties Reserve

The following table reflects the changes in the Company’s Warranty Reserve during the three and six months ended June 30, 2018 and 2017:



	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Warranty reserve, beginning of period	$	95,606		$	93,503		$	94,513		$	93,895
Provision	16,217			13,206			27,744			22,167
Payments	(12,121		)	(11,315		)	(22,555		)	(20,668		)
Warranty reserve, end of period	$	99,702		$	95,394		$	99,702		$	95,394

Segment Disclosures (Tables)

6 Months Ended

Jun. 30, 2018

Segment Reporting [Abstract]

Revenues

The following tables present segment revenues, profit and assets with reconciliations to the amounts reported for the consolidated enterprise, where applicable:



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Revenues:
Homebuilding Mid Atlantic	$	973,677	$	872,148	$	1,816,173	$	1,594,416
Homebuilding North East	147,618		127,541		270,332		233,771
Homebuilding Mid East	363,288		313,237		653,525		556,268
Homebuilding South East	265,880		199,788		500,526		375,846
Mortgage Banking	36,842		31,778		76,163		61,283
Total consolidated revenues	$	1,787,305	$	1,544,492	$	3,316,719	$	2,821,584

Profit before Taxes



	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Income before taxes:
Homebuilding Mid Atlantic	$	112,221		$	100,621		$	203,268		$	165,109
Homebuilding North East	16,777			14,112			32,481			23,218
Homebuilding Mid East	42,174			35,986			69,385			58,145
Homebuilding South East	29,203			22,911			52,440			37,481
Mortgage Banking	19,685			18,004			42,235			33,957
Total segment profit before taxes	220,060			191,634			399,809			317,910
Reconciling items:
Contract land deposit reserve adjustment (1)	592			(2,064		)	2,720			(2,792		)
Equity-based compensation expense (2)	(18,595		)	(10,878		)	(28,104		)	(21,467		)
Corporate capital allocation (3)	53,954			49,646			104,653			95,833
Unallocated corporate overhead	(22,503		)	(23,360		)	(53,787		)	(50,594		)
Consolidation adjustments and other	14,109			9,614			19,311			13,427
Corporate interest expense	(6,031		)	(5,624		)	(12,018		)	(11,188		)
Reconciling items sub-total	21,526			17,334			32,775			23,219
Consolidated income before taxes	$	241,586		$	208,968		$	432,584		$	341,129


(1)	This item represents changes to the contract land deposit impairment reserve, which are not allocated to the reportable segments.


(2)	The increase in equity-based compensation expense in the three and six month periods ended June 30, 2018 was primarily attributable to the issuance of Options and RSUs in the second quarter of 2018. See Note 7 for additional discussion of equity-based compensation.


(3)	This item represents the elimination of the corporate capital allocation charge included in the respective homebuilding reportable segments. The corporate capital allocation charge is based on the segment’s monthly average asset balance, and was as follows for the periods presented:



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Corporate capital allocation charge:
Homebuilding Mid Atlantic	$	31,501	$	31,005	$	61,949	$	60,130
Homebuilding North East	4,580		4,133		8,760		7,947
Homebuilding Mid East	9,057		7,535		17,030		14,277
Homebuilding South East	8,816		6,973		16,914		13,479
Total	$	53,954	$	49,646	$	104,653	$	95,833

Assets



	June 30, 2018			December 31, 2017
Assets:
Homebuilding Mid Atlantic	$	1,139,958		$	1,079,225
Homebuilding North East	155,089			143,008
Homebuilding Mid East	322,718			263,019
Homebuilding South East	315,599			277,705
Mortgage Banking	448,779			397,052
Total segment assets	2,382,143			2,160,009
Reconciling items:
Cash and cash equivalents	417,341			645,087
Deferred taxes	116,295			111,953
Intangible assets and goodwill	50,066			50,144
Contract land deposit reserve	(27,279		)	(29,999		)
Consolidation adjustments and other	70,829			52,085
Reconciling items sub-total	627,252			829,270
Consolidated assets	$	3,009,395		$	2,989,279

Fair Value (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Undesignated Derivative Instruments

The fair value measurement of NVRM's undesignated derivative instruments was as follows:




	June 30, 2018			December 31, 2017
Rate lock commitments:
Gross assets	$	13,770		$	5,400
Gross liabilities	996			1,832
Net rate lock commitments	$	12,774		$	3,568
Forward sales contracts:
Gross assets	$	408		$	992
Gross liabilities	4,307			667
Net forward sales contracts	$	(3,899	)	$	325

Fair Value Measurement

The fair value measurement as of June 30, 2018 was as follows:



	Notional or Principal Amount		Assumed Gain/(Loss) From Loan Sale		Interest Rate Movement Effect		Servicing Rights Value		Security Price Change			Total Fair Value Measurement Gain/(Loss)
Rate lock commitments	$	857,052	$	1,402	$	1,683	$	9,689	$	—		$	12,774
Forward sales contracts	$	1,168,371	—		—		—		(3,899		)	(3,899		)
Mortgages held for sale	$	393,258	881		376		5,291		—			6,548
Total fair value measurement			$	2,283	$	2,059	$	14,980	$	(3,899	)	$	15,423

Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract liability, revenue recognized	$ 90,000
Cumulative-effect adjustment from adoption of ASU 2014-09, net of tax			$ 2,196
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment from adoption of ASU 2014-09, net of tax			2,196
Other Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract cost	20,100		19,500
Homebuilding [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Customer deposits	172,033	$ 167,486	150,033
Restricted cash and cash equivalents	22,130		19,438
Consolidated Joint Venture [Member] \| Homebuilding [Member] \| Other Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash and cash equivalents	$ 1,128		$ 1,069	$ 1,199	$ 1,214

Variable Interest Entities ("VIEs") - Additional Information (Detail) $ in Thousands	Jun. 30, 2018 USD ($) lot	Dec. 31, 2017 USD ($)
Variable Interest Entity [Line Items]
Contract land deposits in cash	$ 388,331	$ 400,428
Variable Interest Entities [Member]
Variable Interest Entity [Line Items]
Maximum range of deposits required under the purchase agreements	10.00%
Power of developers equity holders to direct operating activities of development entity	100.00%
Lots controlled by NVR \| lot	90,100
Contract land deposits in cash under lot purchase Agreements	$ 377,400
Letters of credit related to lots	$ 2,700
Contract on Raw Ground with Landowners [Member]
Variable Interest Entity [Line Items]
Lots controlled by NVR \| lot	9,900
Contract land deposits in cash	$ 10,900
Letters of credit related to land contract	100
Refundable deposits and letters of credit	$ 2,100

Variable Interest Entities ("VIEs") - Total Risk of Loss Related to Contract Land Deposits (Detail) $ in Thousands	Jun. 30, 2018 USD ($) lot	Dec. 31, 2017 USD ($) lot
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure [Abstract]
Contract land deposits	$ 388,331	$ 400,428
Loss reserve on contract land deposits	(27,279)	(29,999)
Contract land deposits, net	361,052	370,429
Contingent obligations in the form of letters of credit	2,798	1,996
Specific performance obligations	1,505	1,505
Total risk of loss	$ 365,355	$ 373,930
Finished lots committed to purchase under specific performance obligations \| lot	10	10

Joint Ventures - Additional Information (Detail) $ in Thousands	Jun. 30, 2018 USD ($) joint_venture lot	Dec. 31, 2017 USD ($)
Joint Ventures [Line Items]
Aggregate investment \| $	$ 40,000
Number of joint ventures \| joint_venture	6
Expected production of finished lots \| lot	7,000
Total lots controlled by company under the joint venture \| lot	3,650
Total lots either under contract with unrelated parties or not under the current contract \| lot	3,350
Additional funding commitments in the aggregate \| $	$ 5,000
Number of joint ventures with additional funding commitment \| joint_venture	3
Number of joint ventures NVR is not primary beneficiary \| joint_venture	5
Other Assets [Member]
Joint Ventures [Line Items]
Aggregate investment \| $	$ 39,700	$ 49,000

Joint Ventures - Condensed Balance Sheets (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Liabilities and equity:
Equity	$ 1,607,571	$ 1,605,492
Total liabilities and shareholders' equity	3,009,395	2,989,279
Consolidated Joint Venture [Member]
Assets:
Cash	1,128	1,069
Other assets	37	37
Assets related to consolidated variable interest entity	1,165	1,106
Liabilities and equity:
Accrued expenses	484	487
Equity	681	619
Total liabilities and shareholders' equity	$ 1,165	$ 1,106

Land Under Development - Additional Information (Detail) $ in Thousands	Jun. 30, 2018 USD ($) parcel lot
Real Estate [Abstract]
Number of raw parcels of land owned \| parcel	4
Carrying value of raw parcels of land	$ 35,292
Number of finished lots expected to be developed from raw parcels of land \| lot	450
Aggregate additional funding commitments related to raw land property under joint development	$ 8,300
Expected development credits that will offset the aggregate additional funding commitments related to raw land property development	$ 4,800

Capitalized Interest - Summary of Interest Costs Incurred, Capitalized, Expensed and Charged to Cost of Sales (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Capitalized Interest Costs, Including Allowance for Funds Used During Construction [Roll Forward]
Interest capitalized, beginning of period	$ 5,545	$ 5,564	$ 5,583	$ 5,106
Interest incurred	6,624	6,580	13,220	13,139
Interest expense	(6,329)	(5,914)	(12,611)	(11,750)
Interest charged to cost of sales	(452)	(278)	(804)	(543)
Interest capitalized, end of period	$ 5,388	$ 5,952	$ 5,388	$ 5,952

Earnings Per Share - Weighted Average Shares and Share Equivalents Used to Calculate Basic and Diluted Earnings Per Share (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Weighted average number of shares outstanding used to calculate basic EPS (in shares)	3,635	3,748	3,655	3,726
Dilutive securities:
Stock options and restricted share units (in shares)	507	454	526	429
Weighted average number of shares and share equivalents outstanding used to calculate diluted EPS (in shares)	4,142	4,202	4,181	4,155

Earnings Per Share - Summary of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Anti-dilutive securities (in shares)	349	9	349	15

Equity-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	May 02, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized	60,000,000		60,000,000			60,000,000
Expiration period			10 years
Compensation cost	$ 18,595	$ 10,878	$ 28,104	$ 21,467
Compensation cost not yet recognized	$ 347,900		$ 347,900
Compensation cost not yet recognized, period			2 years 9 months 18 days
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	166,000		340,000
Employee Stock Option [Member] \| Vesting over 2 Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	34,000
Vesting period	2 years
Vesting percentage	50.00%
Employee Stock Option [Member] \| Vesting over 4 Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	132,000
Vesting period	4 years
Vesting percentage	25.00%
Employee Performance Based Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	166,000
Employee Performance Based Stock Option [Member] \| Vesting over 2 Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	34,000
Vesting period	2 years
Vesting percentage	50.00%
Employee Performance Based Stock Option [Member] \| Vesting over 4 Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	132,000
Vesting period	4 years
Vesting percentage	25.00%
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, value per share			$ 3,022.99
Restricted Stock Units (RSUs) [Member] \| Vesting over 2 Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	2 years
Vesting percentage	50.00%
Performance Based Restricted Stock Unit [Member] \| Vesting over 2 Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	2 years
Vesting percentage	50.00%
Two Thousand Eighteen, Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized					275,000
Shares granted	144,000
Two Thousand Eighteen, Equity Plan [Member] \| Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	72,000
Two Thousand Eighteen, Equity Plan [Member] \| Employee Performance Based Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	72,000
Two Thousand Eighteen, Equity Plan [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized					40,000
Two Thousand Ten, Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	4,000
Two Thousand Ten, Equity Plan [Member] \| Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued	332,000
Shares granted	4,000
Two Thousand Ten, Equity Plan [Member] \| Employee Performance Based Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	0
Two Thousand Ten, Equity Plan [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued	16,000
Two Thousand Fourteen, Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	184,000
Two Thousand Fourteen, Equity Plan [Member] \| Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	90,000		8,000
Two Thousand Fourteen, Equity Plan [Member] \| Employee Stock Option [Member] \| Vesting over 4 Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			4 years
Vesting percentage			25.00%
Two Thousand Fourteen, Equity Plan [Member] \| Employee Stock Option [Member] \| Continued Employment and Return Of Capital Performance [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			50.00%
Two Thousand Fourteen, Equity Plan [Member] \| Employee Stock Option [Member] \| Continued Employment [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			50.00%
Two Thousand Fourteen, Equity Plan [Member] \| Employee Performance Based Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	94,000

Equity-Based Compensation Compensation Plans (Details) shares in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018 $ / shares shares	Jun. 30, 2018 $ / shares shares
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding at beginning of period (Shares)		916
Shares granted	166	340
Exercised (Shares)		(91)
Forfeited (Shares)		(27)
Outstanding at end of period (Shares)	1,138	1,138
Exercisable at end of period (Shares)	371	371
Outstanding at beginning of period (Weighted Average Exercise Price) $ / shares \| $ / shares		$ 1,119.92
Granted (Weighted Average Exercise Price) $ / shares \| $ / shares		3,023.76
Exercised (Weighted Average Exercise Price) $ / shares \| $ / shares		949.64
Forfeited (Weighted Average Exercise Price) $ / shares \| $ / shares		1,300.09
Outstanding at end of period (Weighted Average Exercise Price) $ / shares \| $ / shares	$ 1,697.50	1,697.50
Exercisable at end of period (Weighted Average Exercise Price) $ / shares \| $ / shares	$ 959.65	$ 959.65
Two Thousand Ten, Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	4
Shares granted	16
Two Thousand Ten, Equity Plan [Member] \| Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	4
Two Thousand Ten, Equity Plan [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding at beginning of period (Shares)		10
Shares granted	8	16
Vested (Shares)		(5)
Forfeited (Shares)		0
Outstanding at end of period (Shares)	21	21
Vested, but not issued at end of period (Shares)	0	0

Equity-Based Compensation Black-Scholes Option-Pricing Model Assumptions (Details)	6 Months Ended
	Jun. 30, 2018 $ / shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected option life	5 years 22 days
Risk free interest rate, minimum	2.19%
Risk free interest rate, maximum	2.99%
Expected volatility rate, minimum	16.57%
Expected volatility rate, maximum	18.83%
Expected dividend rate	0.00%
Weighted average grant date fair value per share of Options granted	$ 689.47

Shareholders' Equity - Summary of Changes in Shareholders' Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 1,605,492
Cumulative-effect adjustment from adoption of ASU 2014-09, net of tax					$ 2,196
Net income	$ 203,174	$ 147,877	369,223	$ 250,800
Purchase of common stock for treasury			(483,538)
Equity-based compensation			28,104
Proceeds from Options exercised			86,094
Ending Balance	1,607,571		1,607,571
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			206
Ending Balance	206		206
Additional Paid-In-Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			1,644,197
Equity-based compensation			28,104
Proceeds from Options exercised			86,094
Treasury stock issued upon option exercise and restricted share vesting			(36,699)
Ending Balance	1,721,696		1,721,696
Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			6,231,940
Cumulative-effect adjustment from adoption of ASU 2014-09, net of tax					$ 2,196
Net income			369,223
Ending Balance	6,603,359		6,603,359
Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			(6,270,851)
Purchase of common stock for treasury			(483,538)
Treasury stock issued upon option exercise and restricted share vesting			36,699
Ending Balance	(6,717,690)		(6,717,690)
Deferred Compensation Trust [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			(17,383)
Deferred compensation activity, net			235
Ending Balance	(17,148)		(17,148)
Deferred Compensation Liability [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			17,383
Deferred compensation activity, net			(235)
Ending Balance	$ 17,148		$ 17,148

Shareholders' Equity - Additional Information (Detail) shares in Thousands	6 Months Ended
	Jun. 30, 2018 shares
Equity [Abstract]
Common stock repurchased (in shares)	158
Reissued shares during the period, shares (in shares)	96

Product Warranties Product Warranties - Schedule of Product Warranties Reserves (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Warranty reserve, beginning of period	$ 95,606	$ 93,503	$ 94,513	$ 93,895
Provision	16,217	13,206	27,744	22,167
Payments	(12,121)	(11,315)	(22,555)	(20,668)
Warranty reserve, end of period	$ 99,702	$ 95,394	$ 99,702	$ 95,394

Segment Disclosures - Additional Information (Detail)	6 Months Ended
Segment Disclosures - Additional Information (Detail)	Jun. 30, 2018 segment
Senior Notes due 2022 [Member]
Segment Reporting Information [Line Items]
Senior notes interest rate	3.95%
Senior notes maturity	Sep. 15, 2022
Homebuilding [Member]
Segment Reporting Information [Line Items]
Number of reportable segments	4
Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Number of reportable segments	1

Segment Disclosures - Revenues (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting, Revenue Reconciling Item [Line Items]
Consolidated revenues	$ 1,787,305	$ 1,544,492	$ 3,316,719	$ 2,821,584
Homebuilding [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	1,750,463	1,512,714	3,240,556	2,760,301
Homebuilding [Member] \| Mid Atlantic [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	973,677	872,148	1,816,173	1,594,416
Homebuilding [Member] \| North East [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	147,618	127,541	270,332	233,771
Homebuilding [Member] \| Mid East [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	363,288	313,237	653,525	556,268
Homebuilding [Member] \| South East [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	265,880	199,788	500,526	375,846
Mortgage Banking [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Mortgage Banking	$ 36,842	$ 31,778	$ 76,163	$ 61,283

Segment Disclosures - Income before Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income before taxes	$ 241,586	$ 208,968	$ 432,584	$ 341,129
Equity-based compensation expense (2)			(28,104)	(21,467)
Corporate interest expense	(6,329)	(5,914)	(12,611)	(11,750)
Homebuilding [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income before taxes	223,266	191,337	391,836	308,527
Corporate interest expense	(6,047)	(5,641)	(12,054)	(11,219)
Mortgage Banking [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income before taxes	18,320	17,631	40,748	32,602
Corporate interest expense	(282)	(273)	(557)	(531)
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income before taxes	220,060	191,634	399,809	317,910
Operating Segments [Member] \| Homebuilding [Member] \| Mid Atlantic [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income before taxes	112,221	100,621	203,268	165,109
Operating Segments [Member] \| Homebuilding [Member] \| North East [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income before taxes	16,777	14,112	32,481	23,218
Operating Segments [Member] \| Homebuilding [Member] \| Mid East [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income before taxes	42,174	35,986	69,385	58,145
Operating Segments [Member] \| Homebuilding [Member] \| South East [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income before taxes	29,203	22,911	52,440	37,481
Operating Segments [Member] \| Mortgage Banking [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income before taxes	19,685	18,004	42,235	33,957
Corporate and Reconciling Items [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income before taxes	21,526	17,334	32,775	23,219
Contract land deposit reserve adjustment	592	(2,064)	2,720	(2,792)
Equity-based compensation expense (2)	(18,595)	(10,878)	(28,104)	(21,467)
Corporate capital allocation	53,954	49,646	104,653	95,833
Unallocated corporate overhead	(22,503)	(23,360)	(53,787)	(50,594)
Consolidation adjustments and other	14,109	9,614	19,311	13,427
Corporate interest expense	(6,031)	(5,624)	(12,018)	(11,188)
Corporate and Reconciling Items [Member] \| Homebuilding [Member] \| Mid Atlantic [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate capital allocation	31,501	31,005	61,949	60,130
Corporate and Reconciling Items [Member] \| Homebuilding [Member] \| North East [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate capital allocation	4,580	4,133	8,760	7,947
Corporate and Reconciling Items [Member] \| Homebuilding [Member] \| Mid East [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate capital allocation	9,057	7,535	17,030	14,277
Corporate and Reconciling Items [Member] \| Homebuilding [Member] \| South East [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate capital allocation	$ 8,816	$ 6,973	$ 16,914	$ 13,479

Segment Disclosures - Corporate Capital Allocation Charge (Detail) - Corporate and Reconciling Items [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 53,954	$ 49,646	$ 104,653	$ 95,833
Homebuilding [Member] \| Mid Atlantic [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	31,501	31,005	61,949	60,130
Homebuilding [Member] \| North East [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	4,580	4,133	8,760	7,947
Homebuilding [Member] \| Mid East [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	9,057	7,535	17,030	14,277
Homebuilding [Member] \| South East [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 8,816	$ 6,973	$ 16,914	$ 13,479

Segment Disclosures - Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 3,009,395	$ 2,989,279
Contract land deposit reserve	(27,279)	(29,999)
Homebuilding [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,553,269	2,584,880
Cash and cash equivalents	417,341	645,087
Mortgage Banking [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	456,126	404,399
Cash and cash equivalents	14,209	21,707
Operating Segments [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,382,143	2,160,009
Operating Segments [Member] \| Homebuilding [Member] \| Mid Atlantic [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,139,958	1,079,225
Operating Segments [Member] \| Homebuilding [Member] \| North East [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	155,089	143,008
Operating Segments [Member] \| Homebuilding [Member] \| Mid East [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	322,718	263,019
Operating Segments [Member] \| Homebuilding [Member] \| South East [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	315,599	277,705
Operating Segments [Member] \| Mortgage Banking [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	448,779	397,052
Corporate and Reconciling Items [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	627,252	829,270
Cash and cash equivalents	417,341	645,087
Deferred taxes	116,295	111,953
Intangible assets and goodwill	50,066	50,144
Contract land deposit reserve	(27,279)	(29,999)
Consolidation adjustments and other	$ 70,829	$ 52,085

Fair Value - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value measurement gain/(loss)			$ 15,423		$ 5,824
Homebuilding [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes carrying value	$ 597,373		597,373		597,066
Homebuilding [Member] \| Senior Notes due 2022 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes carrying value	597,373		597,373		597,066
Homebuilding [Member] \| Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Senior Notes due 2022 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes fair value	630,000		630,000		630
Mortgage Banking [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of mortgage loans held for sale	399,806		399,806		352,489
Mortgage Banking [Member] \| Level 2 [Member] \| Not Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value adjustment income (expense)	5,585	$ 3,376	9,599	$ 1,359
Mortgage Banking [Member] \| Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Rate Lock Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	857,052		857,052
Total fair value measurement gain/(loss)			12,774
Mortgage Banking [Member] \| Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Forward Sales Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	1,168,371		1,168,371
Total fair value measurement gain/(loss)			(3,899)
Mortgage Banking [Member] \| Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Mortgages Held for Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	393,258		393,258		350,558
Fair value of mortgage loans held for sale	$ 399,806		399,806		352,489
Total fair value measurement gain/(loss)			$ 6,548		$ 1,931

Fair Value - Undesignated Derivative Instruments (Detail) - Other Assets [Member] - Mortgage Banking [Member] - Level 2 [Member] - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Rate Lock Commitments [Member]
Derivatives, Fair Value [Line Items]
Gross assets	$ 13,770	$ 5,400
Gross liabilities	996	1,832
Net rate lock commitments and forward sales contracts	12,774	3,568
Forward Sales Contracts [Member]
Derivatives, Fair Value [Line Items]
Gross assets	408	992
Gross liabilities	4,307	667
Net rate lock commitments and forward sales contracts	$ (3,899)	$ 325

Fair Value - Fair Value Measurement (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assumed Gain/(Loss) From Loan Sale	$ 2,283
Interest Rate Movement Effect	2,059
Servicing Rights Value	14,980
Security Price Change	(3,899)
Total Fair Value Measurement Gain/(Loss)	15,423	$ 5,824
Mortgage Banking [Member] \| Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Rate Lock Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	857,052
Assumed Gain/(Loss) From Loan Sale	1,402
Interest Rate Movement Effect	1,683
Servicing Rights Value	9,689
Total Fair Value Measurement Gain/(Loss)	12,774
Mortgage Banking [Member] \| Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Forward Sales Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	1,168,371
Security Price Change	(3,899)
Total Fair Value Measurement Gain/(Loss)	(3,899)
Mortgage Banking [Member] \| Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Mortgages Held for Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	393,258	350,558
Assumed Gain/(Loss) From Loan Sale	881
Interest Rate Movement Effect	376
Servicing Rights Value	5,291
Total Fair Value Measurement Gain/(Loss)	$ 6,548	$ 1,931

Debt - Additional Information (Detail)	6 Months Ended
Debt - Additional Information (Detail)	Jun. 30, 2018 USD ($)
Senior Notes due 2022 [Member]
Debt Instrument [Line Items]
Senior notes principal amount	$ 600,000,000
Senior notes maturity date	Sep. 15, 2022
Senior notes interest rate	3.95%
Frequency of senior notes payment	semi-annually in arrears on March 15 and September 15
Senior notes effective interest rate	3.97%
Credit Agreement [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum loan borrowing capacity	$ 200,000,000
Increase in commitment available	$ 300,000,000
Expiration date	Jul. 15, 2021
Debt outstanding	$ 0
Credit Agreement [Member] \| Revolving Credit Facility [Member] \| Sublimit for Issuance of Letters of Credit [Member]
Debt Instrument [Line Items]
Maximum loan borrowing capacity	100,000,000
Letters of credit outstanding	8,500,000
Credit Agreement [Member] \| Revolving Credit Facility [Member] \| Sublimit for Swing Line Commitment [Member]
Debt Instrument [Line Items]
Maximum loan borrowing capacity	25,000,000
Repurchase Agreement [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum loan borrowing capacity	150,000,000
Increase in commitment available	$ 50,000,000
Expiration date	Jul. 24, 2019
Debt outstanding	$ 0
Borrowing base limitations	$ 0

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Tax [Line Items]
Effective tax rate	15.90%	29.20%	14.60%	26.50%
Income tax expense (benefit)	$ 38,412	$ 61,091	$ 63,361	$ 90,329
Excess tax benefit recognized	$ 26,456	$ 16,464	46,022	$ 36,364
Energy Tax Credit Carryforward
Income Tax [Line Items]
Income tax expense (benefit)			$ 6,200

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment		$ 2,196
Forecast \| Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment	$ 100,000