Accumulated Other Comprehensive Income (Loss) - AOCI Reclass to IS (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Salaries and Benefits	$ (57,033)		$ (56,175)		$ (115,248)	$ (121,263)
Provision for Income Tax	(11,224)		(15,006)		(23,197)	(30,937)
Net Income (Loss)	34,083	$ 36,391	46,061	$ 46,842	70,474	92,903
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Net Income (Loss)	(4,793)		(5,082)		(9,520)	(10,247)
Reclassification out of Accumulated Other Comprehensive Income | Amortization of Unrealized Gains(Losses) of Investment Securities Transferred from AFS to HTM
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Interest Income	(6,294)		(6,801)		(12,496)	(13,714)
Provision for Income Tax	1,669		1,803		3,313	3,635
Net Income (Loss)	(4,625)		(4,998)		(9,183)	(10,079)
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Salaries and Benefits	61		62		122	123
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Salaries and Benefits	(291)		(177)		(582)	(352)
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Defined Benefit Plans Adjustment Attributable to Parent
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Salaries and Benefits	(230)		(115)		(460)	(229)
Provision for Income Tax	62		31		123	61
Net Income (Loss)	$ (168)		$ (84)		$ (337)	$ (168)