Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 81,169	$ 103,360
AFS investment securities
Net unrealized (losses) gains	(29,889)	36,478
Amortization of net unrealized losses on AFS securities transferred to HTM securities	2,060	2,267
Reclassification adjustment for net losses realized in net income	197	0
Income tax benefit (expense)	6,885	(9,892)
Other comprehensive (loss) income on AFS securities	(20,746)	28,853
Cash flow hedge derivatives
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	(19,461)	13,763
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	4,823	1,262
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax	(1,688)	(4,694)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	(16,326)	10,331
Defined benefit pension and postretirement obligations
Amortization of prior service cost	(72)	(81)
Amortization of actuarial (gain) loss	(7)	30
Income tax (expense) benefit	(1,633)	79
Other comprehensive (loss) income on pension and postretirement obligations	(1,712)	27
Total other comprehensive (loss) income	(38,785)	39,211
Comprehensive income	$ 42,384	$ 142,571