Inventories - Inventory Impairments (Details) - USD ($) $ in Thousands	3 Months Ended						12 Months Ended
	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Inventory [Line Items]
Inventory Impairments	$ 325	$ 610	$ 10,002	$ 11,098	$ 200	$ 550	$ 0	$ 935	$ 21,850
Homebuilding Segment
Inventory [Line Items]
Inventory Impairments							0	935	21,850
Homebuilding Segment | Housing completed or under construction
Inventory [Line Items]
Inventory Impairments							0	535	4,504
Homebuilding Segment | Land and land under development
Inventory [Line Items]
Inventory Impairments							0	400	17,346
Homebuilding Segment | West | Housing completed or under construction
Inventory [Line Items]
Inventory Impairments							0	100	2,860
Homebuilding Segment | West | Land and land under development
Inventory [Line Items]
Inventory Impairments							0	0	16,198
Homebuilding Segment | Mountain | Housing completed or under construction
Inventory [Line Items]
Inventory Impairments							0	0	417
Homebuilding Segment | Mountain | Land and land under development
Inventory [Line Items]
Inventory Impairments							0	400	958
Homebuilding Segment | East | Housing completed or under construction
Inventory [Line Items]
Inventory Impairments							0	435	1,227
Homebuilding Segment | East | Land and land under development
Inventory [Line Items]
Inventory Impairments							$ 0	$ 0	$ 190