Segment Reporting - Reconciliation of Pretax Operating Income From Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Income before income taxes	$ 126,018	$ 62,806	$ 286,218	$ 192,743
Homebuilding:
Segment Reporting Information [Line Items]
Income before income taxes	101,650	48,691	236,240	151,360
Financial Services:
Segment Reporting Information [Line Items]
Income before income taxes	24,368	14,115	49,978	41,383
Operating Segments | Homebuilding: | West
Segment Reporting Information [Line Items]
Income before income taxes	59,120	34,898	144,441	103,448
Operating Segments | Homebuilding: | Mountain
Segment Reporting Information [Line Items]
Income before income taxes	48,053	31,391	111,372	89,077
Operating Segments | Homebuilding: | East
Segment Reporting Information [Line Items]
Income before income taxes	6,020	2,136	9,993	5,761
Operating Segments | Financial Services: | Mortgage operations
Segment Reporting Information [Line Items]
Income before income taxes	20,809	8,468	46,558	19,700
Operating Segments | Financial Services: | Other
Segment Reporting Information [Line Items]
Income before income taxes	3,559	5,647	3,420	21,683
Corporate | Homebuilding:
Segment Reporting Information [Line Items]
Income before income taxes	$ (11,543)	$ (19,734)	$ (29,566)	$ (46,926)