Income Taxes - Company's Net Deferred Tax Asset Recorded in Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Allowance for losses and reserve for unfunded commitments	$ 26,361	$ 28,159
Deferred compensation	1,758	1,786
Accrued pension liability	0	383
Other accrued expenses	1,994	1,537
Additional unfunded status of the supplemental retirement plans	13,693	13,275
Operating lease liability	7,769	8,270
State taxes	3,251	2,870
Share based compensation	952	837
Nonaccrual interest	937	725
Acquisition cost basis	506	2,372
Unrealized loss on securities	116	0
Tax credits	513	513
Tax credit related to operating losses	1,131	1,131
Other	813	327
Total deferred tax assets	59,794	62,185
Deferred tax liabilities:
Securities income	(762)	(762)
Depreciation	(6,198)	(7,231)
Right of use asset	(7,588)	(8,232)
Funded pension liability	(709)	0
Securities accretion	(846)	(702)
Mortgage servicing rights valuation	(1,726)	(1,490)
Unrealized gain on securities	0	(5,671)
Core deposit intangible	(3,248)	(4,812)
Junior subordinated debt	(1,422)	(1,553)
Prepaid expenses and other	(488)	(532)
Total deferred tax liability	(22,987)	(30,985)
Net deferred tax asset	$ 36,807	$ 31,200