Securities Available-for-Sale - Continuous Unrealized Loss Position for 12 Months or Less and 12 Months and Longer (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 10,813	$ 35,969
Less Than 12 Months, Unrealized Losses	29	150
12 Months or Longer, Fair Value	14,380	65,325
12 Months or Longer, Unrealized Losses	135	520
Total, Fair Value	25,193	101,294
Total, Unrealized Losses	164	670
SBA Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	0	13,839
Less Than 12 Months, Unrealized Losses	0	42
12 Months or Longer, Fair Value	95	30,200
12 Months or Longer, Unrealized Losses	1	247
Total, Fair Value	95	44,039
Total, Unrealized Losses	1	289
U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	9,228	18,188
Less Than 12 Months, Unrealized Losses	14	50
12 Months or Longer, Fair Value	14,285	33,617
12 Months or Longer, Unrealized Losses	134	267
Total, Fair Value	23,513	51,805
Total, Unrealized Losses	148	317
Privately Issued Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or Longer, Fair Value	0	210
12 Months or Longer, Unrealized Losses	0	4
Total, Fair Value	0	210
Total, Unrealized Losses	0	4
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	1,585	3,942
Less Than 12 Months, Unrealized Losses	15	58
12 Months or Longer, Fair Value	0	1,298
12 Months or Longer, Unrealized Losses	0	2
Total, Fair Value	1,585	5,240
Total, Unrealized Losses	$ 15	$ 60