CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 101,292	$ 47,555	$ 34,767
Available-for-sale investment securities:
Gross unrealized holding (loss) gain arising in the period	(161,730)	(26,985)	11,394
Related tax benefit (expense)	37,733	5,777	(2,393)
Reclassification adjustment for net loss included in net income	61	862	368
Related tax expense	(14)	(192)	(77)
Net effect on other comprehensive (loss) income	(123,950)	(20,538)	9,292
Defined benefit plans:
Net gain (loss) arising during the period	76	2,318	(1,072)
Related tax (expense) benefit	(18)	(518)	225
Amortization of unrecognized loss on service benefit plans	63	103	127
Related tax benefit	(15)	(23)	(27)
Reclassification from accumulated other comprehensive income ("AOCI")	185	143	1,054
Related tax benefit	(43)	(32)	(221)
Net effect on other comprehensive income	248	1,991	86
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Net gains (losses) arising during the period	10,606	6,999	(8,376)
Related tax (expense) benefit	(2,421)	(1,407)	1,759
Net effect on other comprehensive income (loss)	8,185	5,592	(6,617)
Total other comprehensive (loss) income, net of tax	(115,517)	(12,955)	2,761
Total comprehensive (loss) income	$ (14,225)	$ 34,600	$ 37,528