Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Securities available-for-sale, amortized cost	$ 1,073,074	$ 1,019,230
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)	90,825,175	90,643,206
Common stock, shares outstanding (in shares)	77,240,215	79,508,265
Treasury stock shares (in shares)	13,600,960	11,134,941