Accumulated Other Comprehensive Income - Schedule of Changes in Accumulated Other Comprehensive Income (Loss) by Component Net of Tax (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized holding gain (loss) on available-for-sale securities arising during the period, Pretax	$ (2,050)	$ 1,094	$ 1,803
Unrealized gain (loss) on securities transferred from available-for-sale to held to maturity, Pretax	86	63	75
Beginning balance, After-tax	986
Other comprehensive (loss) income	(3,111)	914	1,484
Ending Balance, After-tax	(2,125)	986
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, Pretax	1,249	92	(1,786)
Unrealized holding gain (loss) on available-for-sale securities arising during the period, Pretax	(2,050)	1,094	1,803
Unrealized gain (loss) on securities transferred from available-for-sale to held to maturity, Pretax	(1,976)
Amortization of held-to-maturity discount resulting from transfer, Pretax	86	63	75
Total other comprehensive income (loss), Pretax	(3,940)	1,157	1,878
Ending balance, Pretax	(2,691)	1,249	92
Beginning balance, Tax Effect	(263)	(20)	374
Unrealized holding gain (loss) on available-for-sale securities arising during the period, Tax Effect	432	(230)	(378)
Unrealized gain (loss) on securities transferred from available-for-sale to held to maturity, Tax Effect	415
Amortization of held-to-maturity discount resulting from transfer, Tax Effect	(18)	(13)	(16)
Total other comprehensive income (loss), Tax Effect	829	(243)	(394)
Ending Balance, Tax Effect	566	(263)	(20)
Beginning balance, After-tax	986	72	(1,412)
Unrealized holding gain (loss) on available-for-sale securities arising during the period, After-Tax	(1,618)	864	1,425
Unrealized gain (loss) on securities transferred from available-for-sale to held to maturity, After Tax	(1,561)
Amortization of held-to-maturity discount resulting from transfer, After-tax	68	50	59
Other comprehensive (loss) income	(3,111)	914	1,484
Ending Balance, After-tax	$ (2,125)	$ 986	$ 72