Note 19 - Plant Consolidations - Restructuring Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee severance		$ 196	$ 247
Relocation		1,204	857
Lease termination		356
Workforce training			373
Plant infrastructure			79
Total restructuring costs		1,756	1,556
Newburyport, Massachusetts Facility [Member]
Employee severance		178
Relocation	420	1,138
Lease termination		356
Workforce training
Plant infrastructure
Total restructuring costs	$ 420	1,672
Rancho Dominguez, California Facility [Member]
Employee severance		18	10
Relocation		66	501
Lease termination
Workforce training
Plant infrastructure
Total restructuring costs		$ 84	511
Grand Rapids Michigan Facility [Member]
Employee severance			237
Relocation			356
Lease termination
Workforce training			373
Plant infrastructure			79
Total restructuring costs			$ 1,045