Summary of Significant Accounting Policies Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Homebuilding operations percent of total revenue									98.00%	98.00%	97.00%
Revenue	$ 742,150	$ 653,345	$ 623,686	$ 481,109	$ 722,485	$ 567,842	$ 558,098	$ 437,857	$ 2,500,290	$ 2,286,282	$ 1,961,971
Gain (Loss) on Hedging Activity									(12,100)	3,600	700
Construction [Member]
Disaggregation of Revenue [Line Items]
Revenue									2,420,348	2,217,197	1,878,572
Land [Member]
Disaggregation of Revenue [Line Items]
Revenue									24,619	16,889	33,706
Financial Services Sector [Member]
Disaggregation of Revenue [Line Items]
Revenue									55,323	52,196	49,693
Financial Services Sector [Member]
Disaggregation of Revenue [Line Items]
Revenue									$ 55,323	$ 52,196	$ 49,693