Note 12 - Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Taxes at federal statutory rate	$ 6,825	$ 17,903	$ 12,955	$ 23,215
Taxes at federal statutory rate, percentage	35.00%	35.00%	35.00%	35.00%
Increase (reduction) in taxes resulting from:
State and local income tax, net of Federal income tax benefit	$ 780	$ 3,584	$ 1,108	$ 4,148
State and local income tax, net of Federal income tax benefit, percentage	4.00%	7.00%	3.00%	6.30%
Other	$ (830)	$ (770)	$ (2,034)	$ (1,031)
Other, percentage	(4.30%)	(1.50%)	(5.50%)	(1.60%)
Total taxes	$ 6,775	$ 20,717	$ 12,029	$ 26,332
Taxes at effective rate, percentage	34.70%	40.50%	32.50%	39.70%