Accumulated Other Comprehensive Loss, Reclassifications out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Reclassification Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Salaries and employee benefits	$ 12,134			$ 12,393			$ 36,081	$ 38,798
Income tax benefit	4,027			4,555			11,748	15,915
Net of tax	12,875	$ 12,551	$ 12,126	14,680	$ 16,372	$ 17,746	37,552	48,798
Reclassification Out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Net of tax	148			82			443	246
Amortization of Pension and Postretirement Benefit Items [Member] | Reclassification Out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Income tax benefit	(51)			(29)			(155)	(87)
Net of tax	148			82			443	246
Amortization of Net Actuarial Gain [Member] | Reclassification Out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Salaries and employee benefits	203			115			608	343
Amortization of Prior Service Cost [Member] | Reclassification Out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Salaries and employee benefits	$ (4)			$ (4)			$ (10)	$ (10)