Accumulated Other Comprehensive Income (Loss), Reclassifications out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024
Reclassification Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Salaries and employee benefits	$ 11,876		$ 12,520		$ 23,770	$ 23,947
Income tax benefit	4,686		3,929		9,129	7,721
Net of tax	15,039	$ 14,275	12,551	$ 12,126	29,314	24,677
Reclassification Out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment Out of Accumulated Other Comprehensive Loss [Abstract]
Net of tax	541		147		760	295
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	(192)		(52)		(267)	(104)
Net of tax	541		147		760	295
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	737		202		1,034	405
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)		$ (3)		$ (7)	$ (6)