Variable Interest Entities ("VIEs") - Total Risk of Loss Related to Contract Land Deposits (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure [Abstract]
Contract land deposits	$ 435,886	$ 441,423
Loss reserve on contract land deposits	(58,781)	(27,572)
Contract land deposits, net	377,105	413,851
Contingent obligations in the form of letters of credit	6,942	5,606
Total risk of loss	$ 384,047	$ 419,457