Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Other Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract cost	$ 24,300	$ 22,500
Home Building Segment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash and cash equivalents	41,820	28,912
Contract liabilities for customer deposits	381,594	240,758
Consolidated Joint Venture | Home Building Segment | Other Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash and cash equivalents	$ 271	$ 269	$ 271	$ 281