CONSOLIDATED STATEMENTS OF CONDITION (CURRENT PERIOD UNAUDITED) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Available-for-sale securities, book value	$ 864,600	$ 1,508,981
Held-to-maturity securities, fair value	537,538	1,380
Loans held for sale	$ 3,380	$ 5,786
Common stock, no par value (dollars per share)	$ 0	$ 0
Common stock, authorized (in shares)	40,000,000	40,000,000
Common stock, issued (in shares)	14,625,041	14,739,956
Common stock, outstanding (in shares)	14,625,041	14,739,956