Note 2 - Summary of Significant Accounting Policies - Net Sales From Continuing Operations by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	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, 2017	Dec. 31, 2016	Dec. 31, 2015
Net sales	$ 35,627	$ 38,804	$ 28,692	$ 29,657	$ 39,179	$ 41,075	$ 39,775	$ 29,358	$ 132,780	$ 149,387	$ 173,160
UNITED STATES
Net sales									122,179	137,411	161,243
CANADA
Net sales									$ 10,601	$ 11,976	$ 11,917