Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	$ (7,566)
Amortization of Net Unrealized Losses on Available-for-Sale Securities Transfered to Held-to-maturity Securities	(1,690)	$ (1,927)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	(7,912)	7,268
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	(746)	1,118
Labor and Related Expense	135,172	123,897
Other Comprehensive Income (Loss), Net of Tax	(36,939)	39,272
Ending Balance	(44,505)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(2,456)	(48,993)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(36,531)	31,832
Amortization of Net Unrealized Losses on Available-for-Sale Securities Transfered to Held-to-maturity Securities	1,690	1,927
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	0	0
Labor and Related Expense	0	0
Other Expenses		0
Other Comprehensive Income (Loss), Tax	8,689	(8,420)
Other Comprehensive Income (Loss), Net of Tax	(26,152)	25,339
Ending Balance	(28,608)	(23,655)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	12,894	(1,268)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	0	0
Amortization of Net Unrealized Losses on Available-for-Sale Securities Transfered to Held-to-maturity Securities	0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	(7,912)	7,268
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	(746)	1,118
Labor and Related Expense	0	0
Other Expenses		0
Other Comprehensive Income (Loss), Tax	(2,083)	2,018
Other Comprehensive Income (Loss), Net of Tax	(10,741)	10,403
Ending Balance	2,153	9,135
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(18,003)	(24,154)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	0	4,770
Amortization of Net Unrealized Losses on Available-for-Sale Securities Transfered to Held-to-maturity Securities	0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax		0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	0	0
Labor and Related Expense	63	63
Other Expenses		(4)
Other Comprehensive Income (Loss), Tax	16	(1,173)
Other Comprehensive Income (Loss), Net of Tax	(47)	3,530
Ending Balance	(18,050)	(20,624)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(7,566)	(74,416)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(36,531)	36,602
Amortization of Net Unrealized Losses on Available-for-Sale Securities Transfered to Held-to-maturity Securities	1,690	1,927
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	(7,912)	7,268
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	(746)	1,118
Labor and Related Expense	63	63
Other Expenses		(4)
Other Comprehensive Income (Loss), Tax	6,623	(7,576)
Other Comprehensive Income (Loss), Net of Tax	(36,939)	39,272
Ending Balance	$ (44,505)	$ (35,144)