CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 21,096	$ 24,888	$ 47,656	$ 48,465
Available-for-sale investment securities:
Gross unrealized holding (loss) gain arising during the period	(12,034)	(42,648)	8,328	(114,284)
Related tax benefit (expense)	3,154	10,238	(1,493)	26,686
Reclassification adjustment for net loss (gain) included in net income	166	44	2,101	(86)
Related tax (expense) benefit	(43)	(10)	(495)	20
Net effect on other comprehensive (loss) income	(8,757)	(32,376)	8,441	(87,664)
Defined benefit plan:
Net gain arising during the period	0	75	0	61
Related tax expense	0	(17)	0	(14)
Amortization of unrecognized loss and service cost on benefit plans	7	17	9	38
Related tax benefit	(2)	(4)	(2)	(9)
Net effect on other comprehensive income	5	71	7	76
Cash flow hedges:
Net gain (loss) arising during the period	1,073	2,104	(283)	7,560
Related tax (expense) benefit	(262)	(492)	51	(1,712)
Net effect on other comprehensive income (loss)	811	1,612	(232)	5,848
Total other comprehensive (loss) gain, net of tax	(7,941)	(30,693)	8,216	(81,740)
Total comprehensive income (loss)	$ 13,155	$ (5,805)	$ 55,872	$ (33,275)