Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2026	Mar. 31, 2026	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2026	Jun. 30, 2025
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance		$ (7,566)			$ (7,566)
Amortization of Net Unrealized Losses on Available-for-Sale Securities Transfered to Held-to-maturity Securities	$ (1,901)		$ (2,059)		(3,590)	$ (3,986)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	(6,506)		1,264		(14,418)	8,532
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	(597)		1,437		(1,343)	2,555
Labor and Related Expense	161,168		126,994		296,341	250,890
Other Comprehensive Income (Loss), Net of Tax	(35,088)	(36,939)	20,847	$ 39,272	(72,027)	60,119
Ending Balance	(79,593)				(79,593)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(28,608)	(2,456)	(23,655)	(48,993)	(2,456)	(48,993)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(36,846)		21,317		(73,377)	53,149
Amortization of Net Unrealized Losses on Available-for-Sale Securities Transfered to Held-to-maturity Securities	1,901		2,059		3,590	3,986
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	0		0		0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	0		0		0	0
Labor and Related Expense	0		0		0	0
Other Expenses			0			0
Other Comprehensive Income (Loss), Tax	8,717		(5,830)		17,407	(14,251)
Other Comprehensive Income (Loss), Net of Tax	(26,228)		17,545		(52,380)	42,884
Ending Balance	(54,836)	(28,608)	(6,109)	(23,655)	(54,836)	(6,109)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	2,153	12,894	9,135	(1,268)	12,894	(1,268)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	0		0		0	0
Amortization of Net Unrealized Losses on Available-for-Sale Securities Transfered to Held-to-maturity Securities	0		0		0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	(6,506)		1,264		(14,418)	8,532
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	(597)		1,437		(1,343)	2,555
Labor and Related Expense	0		0		0	0
Other Expenses			0			0
Other Comprehensive Income (Loss), Tax	(1,709)		650		(3,792)	2,668
Other Comprehensive Income (Loss), Net of Tax	(8,812)		3,352		(19,553)	13,755
Ending Balance	(6,659)	2,153	12,487	9,135	(6,659)	12,487
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(18,050)	(18,003)	(20,624)	(24,154)	(18,003)	(24,154)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	0		0		0	4,770
Amortization of Net Unrealized Losses on Available-for-Sale Securities Transfered to Held-to-maturity Securities	0		0		0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	0		0		0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	0		0		0	0
Labor and Related Expense	63		63		126	126
Other Expenses			(4)			(8)
Other Comprehensive Income (Loss), Tax	15		17		31	(1,157)
Other Comprehensive Income (Loss), Net of Tax	(48)		(50)		(95)	3,480
Ending Balance	(18,098)	(18,050)	(20,674)	(20,624)	(18,098)	(20,674)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(44,505)	(7,566)	(35,144)	(74,416)	(7,566)	(74,416)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(36,846)		21,317		(73,377)	57,919
Amortization of Net Unrealized Losses on Available-for-Sale Securities Transfered to Held-to-maturity Securities	1,901		2,059		3,590	3,986
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	(6,506)		1,264		(14,418)	8,532
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	(597)		1,437		(1,343)	2,555
Labor and Related Expense	63		63		126	126
Other Expenses			(4)			(8)
Other Comprehensive Income (Loss), Tax	7,023		(5,164)		13,647	(12,740)
Other Comprehensive Income (Loss), Net of Tax	(35,088)	(36,939)	20,847	39,272	(72,027)	60,119
Ending Balance	$ (79,593)	$ (44,505)	$ (14,297)	$ (35,144)	$ (79,593)	$ (14,297)