Note 10 - Income Taxes - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
U.S. Federal	$ 0	$ 0	$ 96
U.S. State	(11)	42	51
Foreign	70	375	1,105
Total current income tax expense	59	417	1,252
Deferred:
U.S. Federal	0	(6,734)	(11,312)
U.S. State	0	0	(613)
Foreign	337	(1,894)	(10,503)
Total deferred income tax expense	337	(8,628)	(22,428)
Total	$ 396	$ (8,211)	$ (21,176)