Variable Interest Entities - Total Risk of Loss Related to Contract Land Deposits (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure [Abstract]
Contract land deposits	$ 425,393	$ 400,428
Loss reserve on contract land deposits	(29,216)	(29,999)
Contract land deposits, net	396,177	370,429
Contingent obligations in the form of letters of credit	3,923	1,996
Contingent specific performance obligations	1,505	1,505
Total risk of loss	$ 401,605	$ 373,930