Variable Interest Entities ("VIEs") - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) lot	Mar. 31, 2020 USD ($)	Sep. 30, 2020 USD ($) lot	Dec. 31, 2019 USD ($)
Variable Interest Entity [Line Items]
Contract land deposits in cash	$ 435,886		$ 435,886	$ 441,423
Contract land deposit reserve adjustment	(4,800)	$ 36,400	32,500
Loss Reserve On Contract Land Deposits	$ 58,781		$ 58,781	$ 27,572
Variable Interest Entities [Member]
Variable Interest Entity [Line Items]
Maximum range of deposits required under the purchase agreements	10.00%		10.00%
Power of developers equity holders to direct operating activities of development entity	100.00%		100.00%
Lots controlled by NVR | lot	100,000		100,000
Contract land deposits in cash under lot purchase Agreements	$ 434,200		$ 434,200
Letters of credit related to lots	$ 6,800		$ 6,800
Contract on Raw Ground with Landowners [Member]
Variable Interest Entity [Line Items]
Lots controlled by NVR | lot	6,300		6,300
Contract land deposits in cash	$ 1,700		$ 1,700
Letters of credit related to land contract	100		100
Refundable deposits and letters of credit	$ 1,100		$ 1,100