Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Securities available-for-sale, amortized cost	$ 1,672,440	$ 1,622,173
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)	91,113,634	91,090,614
Common stock, shares outstanding (in shares)	72,390,694	72,742,151
Treasury stock, shares (in shares)	18,722,940	18,348,463