Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Securities available-for-sale, amortized cost	$ 1,227,169	$ 1,595,723
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock shares authorized (in shares)	100,000,000	100,000,000
Common stock shares issued (in shares)	87,072,749	87,002,931
Common stock shares outstanding (in shares)	78,862,106	80,806,116
Treasury stock shares (in shares)	8,210,643	6,196,815