Note 7 - Inventories - Inventory Impairments (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2017	Sep. 30, 2016
Impairment Data; Inventory Impairments							$ 9,390	$ 6,300
Homebuilding Segment [Member]
Impairment Data; Inventory Impairments	$ 4,540		$ 4,850	$ 4,700	$ 1,600		9,390	6,300
Homebuilding Segment [Member] | Reportable Segment, West [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments	1,885						5,985	1,400
Homebuilding Segment [Member] | Reportable Segment, Mountain [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments	370						370
Homebuilding Segment [Member] | Reportable Segment, East [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments	$ 2,285			$ 4,700			$ 3,035	$ 4,900