Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total other comprehensive income (loss)	$ (12,472)	$ 108,875
Income tax benefit (expense)	2,619	(22,863)
Other comprehensive income (loss), net of tax	(9,853)	86,012
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	219,880	195,604
Income tax benefit (expense)	(45,783)	(41,057)
Total reclassifications, net of tax	174,097	154,547
Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	(10,655)	(13,096)
Income tax benefit (expense)	2,237	2,750
Total reclassifications, net of tax	(8,418)	(10,346)
Accumulated other comprehensive income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income (loss), net of tax	(9,853)	86,012
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)	(13,154)	102,099
Income tax benefit (expense)	2,762	(21,440)
Other comprehensive income (loss), net of tax	(10,392)	80,659
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	(9,973)	(4,164)
Income tax benefit (expense)	2,094	874
Total reclassifications, net of tax	(7,879)	(3,290)
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)	682	6,776
Income tax benefit (expense)	(143)	(1,423)
Other comprehensive income (loss), net of tax	539	5,353
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	(682)	(8,932)
Income tax benefit (expense)	143	1,876
Total reclassifications, net of tax	$ (539)	$ (7,056)