Note 7 - Inventories - Inventory Impairments (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017
Impairment Data; Inventory Impairments	$ 11,098	$ 200	$ 550	$ 4,540		$ 4,850	$ 11,848	$ 9,390
Homebuilding Segment [Member]
Impairment Data; Inventory Impairments	11,098			4,540			11,848	9,390
Homebuilding Segment [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments	11,098			4,540			11,848	9,390
Homebuilding Segment [Member] | Reportable Segment, West [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments	10,798			1,885			11,173	5,985
Homebuilding Segment [Member] | Reportable Segment, Mountain [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments				370			175	370
Homebuilding Segment [Member] | Reportable Segment, East [Member] | Housing Completed or Under Construction [Member]
Impairment Data; Inventory Impairments	$ 300			$ 2,285			$ 500	$ 3,035