Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Securities available-for-sale, amortized cost	$ 1,267,731	$ 1,336,345
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)	89,826,317	89,104,022
Common stock, shares outstanding (in shares)	80,501,948	80,893,379
Treasury stock shares (in shares)	9,324,369	8,210,643