Note 7 - Income Taxes - Income Tax Provision (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Federal									$ (15)	$ 148
State									123	71	16
Foreign									303	511	131
Total Current									411	730	147
Federal									15,674	(17,393)	(24)
State									1,230	(1,348)	(2)
Foreign									(60)	(22)	22
Total Deferred									16,844	(18,763)	(4)
Tax provision	$ 20,760	$ (174)	$ (712)	$ (2,619)	$ (18,199)	$ 225	$ 59	$ (118)	$ 17,255	$ (18,033)	$ 143