Other Comprehensive Income (Loss) - Tax Effects of Components in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Before Tax
Other comprehensive (loss) income	$ 2,352	$ (76,948)	$ 17,396	$ (152,398)
Tax Effect
Other comprehensive (loss) income	(665)	21,458	(4,271)	42,472
After Tax
Total other comprehensive income (loss)	1,687	(55,490)	13,125	(109,926)
Unrealized Gains (Losses) on Debt Securities Available for Sale
Before Tax
Other comprehensive income (loss), before reclassifications	4,413	(52,246)	21,954	(132,429)
Other comprehensive (loss) income	(5,141)	(52,040)	11,094	(132,227)
Tax Effect
Other comprehensive income (loss), before reclassifications	(1,248)	14,570	(5,720)	36,938
Other comprehensive (loss) income	1,454	14,513	(2,648)	36,882
After Tax
Other comprehensive income (loss), before reclassifications	3,165	(37,676)	16,234	(95,491)
Total other comprehensive income (loss)	(3,687)	(37,527)	8,446	(95,345)
AOCI, Accumulated Gain (Loss), Debt Securities Available-for-sale, Accretion of Unrealized Gains (Losses), Parent
Before Tax
Reclassification from AOCI, current period	(2)	(4)	(13)	(8)
Tax Effect
Reclassification from AOCI, current period	1	1	4	2
After Tax
Reclassification from AOCI, current period	(1)	(3)	(9)	(6)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Other Reclassifications, Parent
Before Tax
Reclassification from AOCI, current period	(9,552)	210	(10,847)	210
Tax Effect
Reclassification from AOCI, current period	2,701	(58)	3,068	(58)
After Tax
Reclassification from AOCI, current period	(6,851)	152	(7,779)	152
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Before Tax
Other comprehensive income (loss), before reclassifications	4,020	1,149	2,816	5,532
Tax Effect
Other comprehensive income (loss), before reclassifications	(1,137)	(321)	(798)	(1,547)
After Tax
Other comprehensive income (loss), before reclassifications	2,883	828	2,018	3,985
Total other comprehensive income (loss)	2,883	828	2,018	3,985
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent
Before Tax
Reclassification from AOCI, current period	(14)	(14)	(28)	(28)
Tax Effect
Reclassification from AOCI, current period	4	3	8	6
After Tax
Reclassification from AOCI, current period	(10)	(11)	(20)	(22)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent
Before Tax
Reclassification from AOCI, current period	1	(339)	2	(678)
Tax Effect
Reclassification from AOCI, current period	0	95	(1)	190
After Tax
Reclassification from AOCI, current period	1	(244)	1	(488)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent
Before Tax
Other comprehensive income (loss), before reclassifications	3,486	(25,704)	3,512	(24,997)
Other comprehensive (loss) income	3,473	(26,057)	3,486	(25,703)
Tax Effect
Other comprehensive income (loss), before reclassifications	(986)	7,168	(832)	6,941
Other comprehensive (loss) income	(982)	7,266	(825)	7,137
After Tax
Other comprehensive income (loss), before reclassifications	2,500	(18,536)	2,680	(18,056)
Total other comprehensive income (loss)	$ 2,491	$ (18,791)	$ 2,661	$ (18,566)