Joint Ventures - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) lot joint_venture	Dec. 31, 2017 USD ($) lot joint_venture
Joint Ventures [Line Items]
Aggregate investment	$ 29,400	$ 45,500
Number of joint ventures | joint_venture	6	6
Expected production of finished lots | lot	6,800	7,300
Total lots controlled by company under the joint venture | lot	3,500	3,900
Total lots either under contract with unrelated parties or not under the current contract | lot	3,400	3,400
Additional funding commitments in the aggregate	$ 5,000	$ 5,300
Number of joint ventures with additional funding commitment | joint_venture	3	3
Number of joint ventures NVR is not primary beneficiary | joint_venture	5
Other Assets
Joint Ventures [Line Items]
Aggregate investment	$ 29,400	$ 45,200
Cost of Sales
Joint Ventures [Line Items]
Equity Method Investment, Other than Temporary Impairment	7,400
EquityMethodInvestmentOtherThanTemporaryImpairmentCapitalizedInterestPortion	$ 760