Note 8 - Inventories - Inventory Impairments (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	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, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Impairment Data; Inventory Impairments	$ 10,002	$ 11,098	$ 200	$ 550	$ 620	$ 4,540		$ 4,850	$ 3,873	$ 4,700	$ 1,600		$ 21,850	$ 10,010	$ 10,173
Reportable Segment, West [Member]
Impairment Data; Inventory Impairments													19,100	6,000	1,400
Reportable Segment, Mountain [Member]
Impairment Data; Inventory Impairments													1,400	800	1,200
Reportable Segment, East [Member]
Impairment Data; Inventory Impairments													1,400	3,200	7,600
Homebuilding Segment [Member]
Impairment Data; Inventory Impairments													21,850	10,010	10,173
Homebuilding Segment [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments													4,504	7,843	2,328
Homebuilding Segment [Member] | Land and Land Under Development [Member]
Impairment Data; Inventory Impairments													17,346	2,167	7,845
Homebuilding Segment [Member] | Reportable Segment, West [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments													2,860	4,733	364
Homebuilding Segment [Member] | Reportable Segment, West [Member] | Land and Land Under Development [Member]
Impairment Data; Inventory Impairments													16,198	1,252	1,036
Homebuilding Segment [Member] | Reportable Segment, Mountain [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments													417	390	574
Homebuilding Segment [Member] | Reportable Segment, Mountain [Member] | Land and Land Under Development [Member]
Impairment Data; Inventory Impairments													958	380	589
Homebuilding Segment [Member] | Reportable Segment, East [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments													1,227	2,720	1,390
Homebuilding Segment [Member] | Reportable Segment, East [Member] | Land and Land Under Development [Member]
Impairment Data; Inventory Impairments													$ 190	$ 535	$ 6,220