Variable Interest Entities - Additional Information (Detail) $ in Thousands	Dec. 31, 2018 USD ($) lot	Dec. 31, 2017 USD ($)
Variable Interest Entity [Line Items]
Maximum range of deposits required under the purchase agreements	10.00%
Contract land deposits in cash	$ 425,393	$ 400,428
Variable Interest Entities
Variable Interest Entity [Line Items]
Maximum range of deposits required under the purchase agreements	10.00%
Lots controlled by NVR | lot	95,800
Contract land deposits in cash under Lot Purchase Agreements	$ 420,900
Letters of credit related to lots	$ 3,800
Contract on Raw Ground with Landowners
Variable Interest Entity [Line Items]
Lots controlled by NVR | lot	7,500
Contract land deposits in cash	$ 4,500
Letters of credit on raw land contracts	150
Refundable deposits	$ 1,700