Income Taxes - Components of Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets
Allowance for loan losses	$ 1,629	$ 1,632
Other real estate owned	226	433
Pension and post-retirement benefit plans	127	266
Unrealized losses on available-for-sale securities	333	130
Deferred and share-based compensation plans	237	215
Alternative minimum tax credit		134
Fair value adjustments on acquired loans and time deposits resulting from the Merger	969	1,665
Net deferred loan fees	53	65
Other	124	270
Total deferred tax assets	3,698	4,810
Deferred tax liabilities
Depreciation of fixed assets	(359)	(69)
Amortization of goodwill and core deposit intangible asset	(1,050)	(1,218)
Premium on fixed assets acquired in the Merger	(553)	(561)
Recapture of bad debts experience reserve	(178)	(229)
Other	(48)	(391)
Total deferred tax liabilities	(2,188)	(2,468)
Deferred tax assets, net	$ 1,510	$ 2,342