Note 16 - Stockholders' Equity (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Stockholders' Equity Attributable to Parent	$ 1,790,000		$ 1,790,000		$ 1,750,000
Stockholders' Equity, Period Increase (Decrease)			45,700
Net Income (Loss) Attributable to Parent	46,090	$ 38,483	127,084	$ 119,663
Other Comprehensive Income (Loss), Net of Tax	$ 761	$ 185	10,329	$ 2,972
Treasury Stock, Value, Acquired, Cost Method			54,400
Dividends, Common Stock, Cash			$ 42,600