Joint Ventures - Additional Information (Detail) $ in Thousands	Sep. 30, 2019 USD ($) joint_venture lot	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Joint Ventures [Line Items]
Aggregate investment	$ 24,600
Number of joint ventures | joint_venture	6
Expected production of finished lots | lot	6,400
Total lots controlled by company under the joint venture | lot	3,050
Total lots either under contract with unrelated parties or not under the current contract | lot	3,350
Additional funding commitments in the aggregate	$ 4,700
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	$ 24,600	$ 29,400
Home Building [Member]
Joint Ventures [Line Items]
Restricted cash and cash equivalents	18,337	16,982
Accrued expenses and other liabilities	319,347	332,871
Consolidated Joint Venture [Member] | Home Building [Member] | Other Assets [Member]
Joint Ventures [Line Items]
Restricted cash and cash equivalents	293	$ 320	$ 335	$ 1,069
Consolidated Joint Venture [Member] | Home Building [Member] | Accounts Payable and Accrued Liabilities [Member]
Joint Ventures [Line Items]
Accrued expenses and other liabilities	$ 263