Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance		$ (272,799)			$ (272,799)
Investment securities losses (gains), net	$ 0		$ (8)		0	$ (8)
HTM investment securities, net, at amortized cost	(2,289)		(3,273)		(4,556)	(4,381)
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	(34,147)		0		(20,384)	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	3,319		0		4,581	0
Personnel expense	(114,089)		(112,666)		(230,510)	(217,477)
Net other comprehensive loss during period	(58,054)	39,211	(45,764)	$ (126,708)	(18,843)	(172,472)
Ending Balance	(291,642)				(291,642)
AFS Investment Securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(204,339)	(233,192)	(131,968)	(5,266)	(233,192)	(5,266)
Other comprehensive (loss) before reclassifications	(49,066)		(65,038)		(12,588)	(168,321)
Unrealized gains (losses) on AFS securities transferred to HTM securities						(67,604)
Investment securities losses (gains), net			8			(12)
HTM investment securities, net, at amortized cost	2,289		3,273		4,556	4,381
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	0				0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	0				0
Personnel expense	0		0		0	0
Other expense	0		0		0	0
Income tax benefit	11,843		15,998		1,951	59,096
Net other comprehensive loss during period	(34,934)		(45,758)		(6,081)	(172,460)
Ending Balance	(239,273)	(204,339)	(177,726)	(131,968)	(239,273)	(177,726)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	13,691	3,360	0	0	3,360	0
Other comprehensive (loss) before reclassifications	0		0		0	0
Unrealized gains (losses) on AFS securities transferred to HTM securities						0
Investment securities losses (gains), net			0			0
HTM investment securities, net, at amortized cost	0		0		0	0
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	(34,147)				(20,384)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	3,319				4,581
Personnel expense	0		0		0	0
Other expense	0		0		0	0
Income tax benefit	7,867		0		3,173	0
Net other comprehensive loss during period	(22,961)		0		(12,630)	0
Ending Balance	(9,270)	13,691	0	0	(9,270)	0
Defined Benefit Pension and Postretirement Obligations
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(42,940)	(42,968)	(5,057)	(5,051)	(42,968)	(5,051)
Other comprehensive (loss) before reclassifications	0		0		0	0
Unrealized gains (losses) on AFS securities transferred to HTM securities						0
Investment securities losses (gains), net			0			0
HTM investment securities, net, at amortized cost	0		0		0	0
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	0				0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	0				0
Personnel expense	(81)		(81)		(163)	(163)
Other expense	(7)		74		22	147
Income tax benefit	(71)		2		8	4
Net other comprehensive loss during period	(159)		(6)		(132)	(12)
Ending Balance	(43,099)	(42,940)	(5,062)	(5,057)	(43,099)	(5,062)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(233,588)	(272,799)	(137,024)	(10,317)	(272,799)	(10,317)
Other comprehensive (loss) before reclassifications	(49,066)		(65,038)		(12,588)	(168,321)
Unrealized gains (losses) on AFS securities transferred to HTM securities						(67,604)
Investment securities losses (gains), net			8			(12)
HTM investment securities, net, at amortized cost	2,289		3,273		4,556	4,381
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	(34,147)				(20,384)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	3,319				4,581
Personnel expense	(81)		(81)		(163)	(163)
Other expense	(7)		74		22	147
Income tax benefit	19,639		16,000		5,132	59,100
Net other comprehensive loss during period	(58,054)	39,211	(45,764)	(126,708)	(18,843)	(172,472)
Ending Balance	$ (291,642)	$ (233,588)	$ (182,788)	$ (137,024)	$ (291,642)	$ (182,788)