Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Securities available-for-sale, amortized cost (in Dollars)	$ 1,476,424	$ 1,595,723
Common stock, par value (in Dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	87,047,371	87,002,931
Common stock, shares outstanding	78,836,728	80,806,116
Treasury stock, shares	8,210,643	6,196,815