Note 10 - Income Taxes - Reconciliation of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income tax expense	$ 47,893	$ 11,897	$ 55,222	$ 18,312
Effective Income Tax Rate Reconciliation, Percent	40.40%	40.20%	40.50%	40.70%