CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Cash and due from banks, interest-bearing amounts	$ 277,670	$ 124,491
Common stock, par value (in dollars per share)	$ 2.50	$ 2.50
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	41,449,444	41,449,444
Common stock, shares outstanding (in shares)	39,263,460	39,560,304
Treasury stock, shares (in shares)	2,185,984	1,889,140