Note 15 - Income Taxes - Summary of Reconciliation of Income Tax Expense (Benefit) at the Federal Statutory Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Computed federal income taxes at the statutory rate	$ (1,276)	$ 1,313	$ 8,080
State income taxes (net of Federal benefit)	(222)	229	1,408
Enacted rate change	3,851
Other	122	(209)	263
Stock-based compensation	44	27	449
Change in valuation allowance	65	139
Total income tax expense	$ 2,584	$ 1,499	$ 10,200