CONSOLIDATED STATEMENTS OF CONDITION (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Available-for-sale securities, at amortized cost	$ 1,583,075	$ 1,831,791
Securities - held-to-maturity	252,978	261,692
Equity securities, at amortized cost	$ 741	$ 777
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, authorized (in shares)	25,000,000	25,000,000
Common stock, issued (in shares)	14,386,087	14,555,741
Treasury stock, shares (in shares)	128,096	128,749