Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total other comprehensive income (loss)	$ 39,843	$ (8,761)	$ 105,307	$ (21,233)
Income tax benefit (expense)	(8,367)	1,840	(22,114)	4,459
Other comprehensive income (loss), net of tax	31,476	(6,921)	83,193	(16,774)
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	246,089	259,825	480,770	479,705
Income tax benefit (expense)	(53,607)	(55,597)	(102,828)	(101,380)
Total reclassifications, net of tax	192,482	204,228	377,942	378,325
Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	(8,170)	(2,742)	(14,209)	(13,397)
Income tax benefit (expense)	1,716	576	2,984	2,813
Total reclassifications, net of tax	(6,454)	(2,166)	(11,225)	(10,584)
Accumulated other comprehensive income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income (loss), net of tax	31,476	(6,921)	83,193	(16,774)
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)	36,105	(9,442)	101,511	(22,596)
Income tax benefit (expense)	(7,582)	1,983	(21,317)	4,745
Other comprehensive income (loss), net of tax	28,523	(7,459)	80,194	(17,851)
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	(4,432)	(2,061)	(10,413)	(12,034)
Income tax benefit (expense)	931	433	2,187	2,527
Total reclassifications, net of tax	(3,501)	(1,628)	(8,226)	(9,507)
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)	3,738	681	3,796	1,363
Income tax benefit (expense)	(785)	(143)	(797)	(286)
Other comprehensive income (loss), net of tax	2,953	538	2,999	1,077
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	(3,738)	(681)	(3,796)	(1,363)
Income tax benefit (expense)	785	143	797	286
Total reclassifications, net of tax	$ (2,953)	$ (538)	$ (2,999)	$ (1,077)