Note 13 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Tax Expense (Benefit), Total	$ 1,444	$ 6,373	$ 394	$ 8,944
Effective Income Tax Rate Reconciliation, Percent, Total	12.50%	35.90%	10.40%	34.70%
Effective Income Tax Rate Reconciliation, Share-based Compensation, Windfall Tax Benefit, Amount			$ 1,300
Effective Income Tax Rate Reconciliation, Share-based Compensation, Windfall Tax Benefit, Percentage			11.30%
Deferred Tax Assets, Valuation Allowance, Total	$ 0		$ 0		$ 0