Accumulated Other Comprehensive Loss, Reclassifications out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Reclassification Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Salaries and employee benefits	$ 13,283	$ 9,239
Income tax (benefit) expense	5,909	5,625
Net income	17,746	17,089
Reclassification Out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Net income	82	265
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) expense	(29)	(93)
Net income	82	265
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	114	78
Amortization of Prior Service (Cost) Credit [Member] | Reclassification Out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Salaries and employee benefits	$ (3)	$ 280