Reclassification Adjustments Out of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reclassification Adjustments out of AOCI [Abstract]
Net securities (gains) losses	$ 1,131	$ (566)	$ 388
Interest income (expense)	362,190	321,088	315,678
Other noninterest expense	19,795	20,339	24,863
Income tax (benefit) expense	44,161	44,973	28,699
Net Income	151,995	154,885	104,388
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Total reclassifications, net of tax	938	1,478	1,923
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Income tax (benefit) expense	(128)	(145)	(160)
Net Income	385	432	481
(Gains) on AFS securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Net securities (gains) losses	0	0	(3)
Amortization of Unrealized Gains Related to Securities Transfer [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Interest income (expense)	513	577	644
Net Unrealized Losses on Cash Flow Hedges Reclassified to Interest Expense [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Interest income (expense)	0	21	296
Income tax (benefit) expense	0	(5)	(74)
Net Income	0	16	222
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Income tax (benefit) expense	(184)	(343)	(407)
Net Income	553	1,030	1,220
Amortization of Net Losses [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Other noninterest expense	623	1,263	1,535
Amortization of Prior Service Costs [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustments out of AOCI [Abstract]
Other noninterest expense	$ 114	$ 110	$ 92