Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	$ (272,799)
HTM investment securities, net, at amortized cost(a)	9,025	$ 9,870	$ 1,551
Personnel	(468,355)	(454,101)	(426,687)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax	(956)	(54)	0
Net other comprehensive income (loss) during period	101,703	(262,483)	(22,935)
Ending Balance	(171,096)	(272,799)
Fair value adjustment on cash flow hedges	(13,254)	3,626	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	13,930	(212)	0
AFS Investment Securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(233,192)	(5,266)	41,325
Other comprehensive income (loss) before reclassifications	41,145	(250,273)	(63,714)
Unrealized (losses) on AFS securities transferred to HTM securities		(67,604)
Investment securities losses, net	64,940	1,922	16
HTM investment securities, net, at amortized cost(a)	9,025	9,870	1,551
Personnel	0	0	0
Other Expenses	0	0	0
Other Comprehensive Income (Loss), Tax	(30,560)	78,159	15,557
Net other comprehensive income (loss) during period	84,550	(227,926)	(46,591)
Ending Balance	(148,641)	(233,192)	(5,266)
Fair value adjustment on cash flow hedges	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	0	0
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	3,360	0	0
Other comprehensive income (loss) before reclassifications	0	0	0
Unrealized (losses) on AFS securities transferred to HTM securities			0
Investment securities losses, net	0	0	0
HTM investment securities, net, at amortized cost(a)	0	0	0
Personnel	0	0	0
Other Expenses	0	0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax	(956)	(54)	0
Net other comprehensive income (loss) during period	(280)	3,360	0
Ending Balance	3,080	3,360	0
Fair value adjustment on cash flow hedges	(13,254)	3,626
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	13,930	(212)
Defined Benefit Pension and Postretirement Obligations
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(42,968)	(5,051)	(28,707)
Other comprehensive income (loss) before reclassifications	24,091	(51,745)	25,519
Unrealized (losses) on AFS securities transferred to HTM securities		0
Investment securities losses, net	0	0	0
HTM investment securities, net, at amortized cost(a)	0	0	0
Personnel	(326)	(325)	1,346
Other Expenses	(29)	658	4,594
Other Comprehensive Income (Loss), Tax	(6,304)	13,495	(7,803)
Net other comprehensive income (loss) during period	17,432	(37,917)	23,656
Ending Balance	(25,535)	(42,968)	(5,051)
Fair value adjustment on cash flow hedges	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	0	0
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(272,799)	(10,317)	12,618
Other comprehensive income (loss) before reclassifications	65,236	(302,018)	(38,195)
Unrealized (losses) on AFS securities transferred to HTM securities		(67,604)
Investment securities losses, net	64,940	1,922	16
HTM investment securities, net, at amortized cost(a)	9,025	9,870	1,551
Personnel	(326)	(325)	1,346
Other Expenses	(29)	658	4,594
Other Comprehensive Income (Loss), Tax	(37,820)	91,601	7,754
Net other comprehensive income (loss) during period	101,703	(262,483)	(22,935)
Ending Balance	$ (171,096)	(272,799)	$ (10,317)
Fair value adjustment on cash flow hedges		3,626
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax		$ (212)