Joint Ventures - Additional Information (Detail) $ in Thousands	Sep. 30, 2021 USD ($) lot joint_venture	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Joint Ventures [Line Items]
Aggregate investment	$ 20,800
Number of joint ventures | joint_venture	4
Expected production of finished lots | lot	2,300
Total lots controlled by company under the joint venture | lot	1,950
Total lots either under contract with unrelated parties or not under the current contract | lot	350
Additional funding commitments in the aggregate	$ 2,900
Number of joint ventures NVR is not primary beneficiary | joint_venture	3
Other Assets
Joint Ventures [Line Items]
Aggregate investment	$ 20,800	$ 23,600
Home Building Segment
Joint Ventures [Line Items]
Restricted cash and cash equivalents	41,820	28,912
Accrued expenses and other liabilities	416,266	440,671
Consolidated Joint Venture | Home Building Segment | Other Assets
Joint Ventures [Line Items]
Restricted cash and cash equivalents	271	$ 269	$ 271	$ 281
Consolidated Joint Venture | Home Building Segment | Accounts Payable and Accrued Liabilities
Joint Ventures [Line Items]
Accrued expenses and other liabilities	$ 250