Note 8 - Inventories (Details Textual) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Inventory Write-down	$ 325	$ 0	$ 0	$ 610	$ 10,002	$ 11,098	$ 200	$ 550	$ 620	$ 4,540	$ 0	$ 4,850	$ 935	$ 21,850	$ 10,010
Reportable Segment, East [Member]
Inventory Write-down													$ 400	$ 1,400
Number of Projects or Properties With Inventory Impairments During Period													2	5
Reportable Segment, Mountain [Member]
Inventory Write-down													$ 400	$ 1,400
Number of Projects or Properties With Inventory Impairments During Period													1	3
Reportable Segment, West [Member]
Inventory Write-down													$ 100	$ 19,100
Number of Projects or Properties With Inventory Impairments During Period													1	7