Insurance and Construction Defect Claim Reserves - Summary of Insurance and Defect Claim Reserves Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Movement in Liability for Future Policy Benefits [Roll Forward]
Balance at beginning of period	$ 60,415,000	$ 55,308,000	$ 52,686,000
Expense provisions	15,403,000	12,650,000	11,213,000
Cash payments, net of recoveries	(5,764,000)	(8,493,000)	(8,591,000)
Adjustments	0	950,000	0
Balance at end of period	$ 70,054,000	$ 60,415,000	$ 55,308,000