Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Allowance for credit losses	$ 14,990	$ 17,486
Post-retirement benefits	6,002	5,974
Deferred compensation	3,619	3,519
Retirement Income Maintenance plan	3,062	2,767
ESOP	990	810
Stock-based compensation	2,386	2,288
Reserve for uncollected interest	35	28
Net unrealized losses on debt securities and defined benefit plans	70,060	17,809
Federal and State NOLs	13,333	9,667
Alternative minimum assessment carryforwards	2,156	2,156
Charitable contribution carryforward	3,514	4,529
Purchase accounting	2,805	1,551
Lease liability	5,264	5,462
Other items	7,002	4,077
Gross deferred tax assets	135,218	78,123
Valuation allowance	(1,965)	(1,965)
Total deferred tax assets, net	133,253	76,158
Deferred tax liabilities:
Pension expense	68,825	61,530
Depreciation	5,945	6,655
Deferred loan costs	14,724	10,630
Intangible assets	1,616	1,594
Lease right-of-use asset	4,958	5,191
Other items	286	307
Total gross deferred tax liabilities	96,354	85,907
Net deferred tax asset (liability)	$ 36,899
Net deferred tax asset (liability)		$ (9,749)