Income Taxes - Summary of Net Deferred Tax Asset (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Allowance for credit losses	$ 17,837	$ 21,300
Stock based compensation plans	1,446	985
Purchase accounting fair market value adjustments	1,487	2,174
Non-accrued interest	504	664
Deferred compensation	2,796	2,570
Loss on equity securities	136	50
Federal net operating loss carryforward	303	875
Unrealized loss on pension plans	0	13
Unrealized loss on derivatives	0	42
Other, net	514	508
Gross deferred tax assets	25,023	29,181
Deferred tax liabilities:
Core deposit intangible from acquired companies	705	852
Undistributed income from subsidiary not consolidated for tax return purposes (REIT)	903	852
Deferred loan costs	2,150	1,822
Depreciation and amortization	1,660	793
Prepaid expenses	824	578
Unrealized gain on investment securities	1,228	4,746
Other	235	260
Gross deferred tax liabilities	7,705	9,903
Net deferred tax assets	$ 17,318	$ 19,278