Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Securities available-for-sale, amortized cost	$ 1,330,232	$ 1,443,730
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)	90,155,230	90,064,382
Common stock, shares outstanding (in shares)	79,420,267	79,729,419
Treasury stock shares (in shares)	10,734,963	10,334,963