Other Comprehensive Income - Schedule of Reclassified Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Losses on sales of securities available for sale, net	$ (16,798)	$ (333,170)	$ (3,157)
Tax benefit (expense)	(36,205)	63,309	(51,719)
Net income from discontinued operations	0	294,866	13,248
Net of tax	119,561	232,177	199,759
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net of tax	(47,765)	(280,932)	(3,445)
Unrealized losses on available-for-sale securities | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Losses on sales of securities available for sale, net	(16,798)	(333,170)	(3,157)
Total before tax	(16,798)	(333,170)	(3,157)
Tax benefit (expense)	4,653	74,630	873
Net of tax	(12,145)	(258,540)	(2,284)
Unrealized (losses) gains on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	(52,151)	(48,795)	9,580
Tax benefit (expense)	14,446	13,517	(2,693)
Interest income	(52,151)	(48,795)	9,580
Net of tax	(37,705)	(35,278)	6,887
Amortization of defined benefit pension items | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net periodic pension cost - see Note 15	(7,069)	(9,563)	(23,077)
BEP and Defined Benefit Plan curtailment gain | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net income from discontinued operations	0	15,908	0
Accretion of prior service credit | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	2,884	17,905	(11,195)
Tax benefit (expense)	(799)	(5,019)	3,147
Net periodic pension cost - see Note 15	9,953	11,560	11,882
Net of tax	$ 2,085	$ 12,886	$ (8,048)