Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Allowance for credit losses, loans and leases	$ 17,343	$ 15,739
Deferred compensation	1,959	2,004
Actuarial adjustments on retirement benefits*	4,043	3,982
State net operating losses	3,348	6,348
Other-than-temporary impairments on equity securities	98	120
Net unrealized holding losses on securities available-for-sale and swaps	12,471	370
Lease liability	7,275	7,317
Other deferred tax assets	2,016	1,526
Gross deferred tax assets	48,553	37,406
Valuation allowance	(2,975)	(5,558)
Total deferred tax assets, net of valuation allowance	45,578	31,848
Deferred tax liabilities:
Mortgage servicing rights	1,785	1,671
Retirement plans	4,907	5,419
Deferred loan fees and costs	897	65
Acquisition-related fair value adjustments	902	1,093
Intangible assets	3,742	3,204
Depreciation	1,575	1,083
Right of use asset	6,596	6,650
Other deferred tax liabilities	1,045	1,241
Total deferred tax liabilities	21,449	20,426
Net deferred tax assets	$ 24,129	$ 11,422