Loans - Schedule of Average Recorded Investment in Impaired Loans and Related Interest Income Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Average recorded investment:
Average recorded investment in impaired loans	$ 1,274	$ 4,386	$ 1,533	$ 5,258
Interest income recognized:
Interest income recognized on a cash basis on impaired loans	11	32	37	122
Commercial [Member]
Average recorded investment:
Average recorded investment in impaired loans	255	1,237	258	1,745
Interest income recognized:
Interest income recognized on a cash basis on impaired loans		3	2	22
Commercial Real Estate [Member]
Average recorded investment:
Average recorded investment in impaired loans	173	2,199	198	2,557
Interest income recognized:
Interest income recognized on a cash basis on impaired loans	2	20	6	71
Residential Real Estate [Member]
Average recorded investment:
Average recorded investment in impaired loans	715	822	781	822
Interest income recognized:
Interest income recognized on a cash basis on impaired loans	7	7	23	23
Construction & Land Development [Member]
Average recorded investment:
Average recorded investment in impaired loans			164
Consumer [Member]
Average recorded investment:
Average recorded investment in impaired loans	131	128	132	134
Interest income recognized:
Interest income recognized on a cash basis on impaired loans	$ 2	$ 2	$ 6	$ 6