Note 8 - Inventories - Inventory Impairments (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, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Impairment Data; Inventory Impairments	$ 325	$ 0	$ 0	$ 610	$ 10,002	$ 11,098	$ 200	$ 550	$ 620	$ 4,540	$ 0	$ 4,850	$ 935	$ 21,850	$ 10,010
Reportable Segment, West [Member]
Impairment Data; Inventory Impairments													100	19,100
Reportable Segment, Mountain [Member]
Impairment Data; Inventory Impairments													400	1,400
Reportable Segment, East [Member]
Impairment Data; Inventory Impairments													400	1,400
Homebuilding Segment [Member]
Impairment Data; Inventory Impairments													935	21,850	10,010
Homebuilding Segment [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments													535	4,504	7,843
Homebuilding Segment [Member] | Land and Land Under Development [Member]
Impairment Data; Inventory Impairments													400	17,346	2,167
Homebuilding Segment [Member] | Reportable Segment, West [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments													100	2,860	4,733
Homebuilding Segment [Member] | Reportable Segment, West [Member] | Land and Land Under Development [Member]
Impairment Data; Inventory Impairments													0	16,198	1,252
Homebuilding Segment [Member] | Reportable Segment, Mountain [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments													0	417	390
Homebuilding Segment [Member] | Reportable Segment, Mountain [Member] | Land and Land Under Development [Member]
Impairment Data; Inventory Impairments													400	958	380
Homebuilding Segment [Member] | Reportable Segment, East [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments													435	1,227	2,720
Homebuilding Segment [Member] | Reportable Segment, East [Member] | Land and Land Under Development [Member]
Impairment Data; Inventory Impairments													$ 0	$ 190	$ 535