Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total other comprehensive income (loss)	$ (8,761)	$ (37,199)	$ (21,233)	$ 71,676
Income tax benefit (expense)	1,840	7,811	4,459	(15,052)
Other comprehensive income (loss), net of tax	(6,921)	(29,388)	(16,774)	56,624
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	259,825	242,382	479,705	437,986
Income tax benefit (expense)	(55,597)	(51,328)	(101,380)	(92,385)
Total reclassifications, net of tax	204,228	191,054	378,325	345,601
Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	(2,742)	(6,842)	(13,397)	(19,938)
Income tax benefit (expense)	576	1,437	2,813	4,187
Total reclassifications, net of tax	(2,166)	(5,405)	(10,584)	(15,751)
Accumulated other comprehensive income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income (loss), net of tax	(6,921)	(29,388)	(16,774)	56,624
Net unrealized gains and (losses) on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total other comprehensive income (loss)	(9,442)	(38,270)	(22,596)	63,829
Income tax benefit (expense)	1,983	8,036	4,745	(13,404)
Other comprehensive income (loss), net of tax	(7,459)	(30,234)	(17,851)	50,425
Net unrealized gains and (losses) on available-for-sale securities | Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	(2,061)	(5,771)	(12,034)	(9,935)
Income tax benefit (expense)	433	1,212	2,527	2,086
Total reclassifications, net of tax	(1,628)	(4,559)	(9,507)	(7,849)
Net benefit plan assets and (obligations) recognized in shareholders' equity
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total other comprehensive income (loss)	681	1,071	1,363	7,847
Income tax benefit (expense)	(143)	(225)	(286)	(1,648)
Other comprehensive income (loss), net of tax	538	846	1,077	6,199
Net benefit plan assets and (obligations) recognized in shareholders' equity | Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	(681)	(1,071)	(1,363)	(10,003)
Income tax benefit (expense)	143	225	286	2,101
Total reclassifications, net of tax	$ (538)	$ (846)	$ (1,077)	$ (7,902)