Loans - Schedule of Average Recorded Investment in Impaired Loans and Related Interest Income Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Average recorded investment:
Average recorded investment in impaired loans	$ 1,474	$ 5,285	$ 1,480	$ 5,699
Interest income recognized:
Interest income recognized on a cash basis on impaired loans	13	40	26	90
Commercial [Member]
Average recorded investment:
Average recorded investment in impaired loans	255	1,979	261	2,002
Interest income recognized:
Interest income recognized on a cash basis on impaired loans	1	9	2	19
Commercial Real Estate [Member]
Average recorded investment:
Average recorded investment in impaired loans	200	2,337	212	2,738
Interest income recognized:
Interest income recognized on a cash basis on impaired loans	2	21	4	51
Residential Real Estate [Member]
Average recorded investment:
Average recorded investment in impaired loans	780	834	819	822
Interest income recognized:
Interest income recognized on a cash basis on impaired loans	8	8	16	16
Construction & Land Development [Member]
Average recorded investment:
Average recorded investment in impaired loans	109		55
Consumer [Member]
Average recorded investment:
Average recorded investment in impaired loans	130	135	133	137
Interest income recognized:
Interest income recognized on a cash basis on impaired loans	$ 2	$ 2	$ 4	$ 4