Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current [Abstract]
Federal	$ 51,077	$ 35,483	$ 36,358
State	12,934	8,626	9,768
Total Current	64,011	44,109	46,126
Deferred [Abstract]
Federal	(15,862)	507	(14,021)
State	(3,988)	357	(3,406)
Total Deferred	(19,850)	864	(17,427)
Total income tax expense	44,161	44,973	28,699
Deferred tax assets [Abstract]
Allowance for loan losses	24,792	22,479
Lease liability	6,273	6,744
Deferred compensation	9,181	9,584
Loan fees	33,389	12,936
Stock-based compensation expense	2,822	2,679
Unrealized losses on securities	53,663	1,482
Other	6,027	7,109
Total deferred tax assets	136,147	63,013
Deferred tax liabilities [Abstract]
Pension benefits	13,103	16,137
Lease right-of-use asset	5,877	5,681
Amortization of intangible assets	14,112	13,187
Premises and equipment, primarily due to accelerated depreciation	4,889	4,962
Other	846	1,008
Total deferred tax liabilities	38,827	40,975
Net deferred tax asset at year-end	97,320	22,038	15,117
Net deferred tax asset at beginning of year	22,038	15,117
Increase in net deferred tax asset	75,282	6,921
Income tax reconciliation [Abstract]
Federal income tax at statutory rate	41,193	41,971	27,948
Tax exempt income	(984)	(1,014)	(981)
Net increase in cash surrender value of life insurance	(1,215)	(1,230)	(1,135)
Federal tax credits	(2,417)	(1,884)	(1,705)
State taxes, net of federal tax benefit	7,067	7,097	5,026
Other, net	517	33	(454)
Total income tax expense	44,161	44,973	28,699
Reconciliation of gross unrecognized tax benefits [Roll Forward]
Beginning balance	1,545	1,178
Additions for tax positions of prior years	3	80
Current period tax positions	394	287
Ending balance	1,942	1,545	$ 1,178
Amount that would affect the effective tax rate if recognized, gross of tax	$ 1,535	$ 1,221
State and Local Jurisdiction [Member]
Income Tax Examination [Abstract]
Tax years under examination	2015 2016 2017 2018 2019