Inventories - Inventory Impairments (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Inventory [Line Items]
Total inventory impairments			$ 610	$ 0	$ 610
Homebuilding:
Inventory [Line Items]
Total inventory impairments	$ 0	$ 0		0	610
Housing Completed or Under Construction | Homebuilding: | West
Inventory [Line Items]
Total inventory impairments	0	0		0	0
Housing Completed or Under Construction | Homebuilding: | Mountain
Inventory [Line Items]
Total inventory impairments	0	0		0	400
Housing Completed or Under Construction | Homebuilding: | East
Inventory [Line Items]
Total inventory impairments	$ 0	$ 0		$ 0	$ 210