Accumulated Other Comprehensive Loss, Reclassifications out of Accumulated Other Comprehensive Loss (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 Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Salaries and employee benefits	$ 12,520		$ 13,122		$ 23,947	$ 26,405
Income tax benefit	3,929		5,451		7,721	11,360
Net of tax	12,551	$ 12,126	16,372	$ 17,746	24,677	34,118
Reclassification Out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Net of tax	147		82		295	164
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	(52)		(29)		(104)	(58)
Net of tax	147		82		295	164
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	202		114		405	228
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	$ (3)		$ (3)		$ (6)	$ (6)