Securities Available-for-Sale - Continuous Unrealized Loss Position for 12 Months or Less and 12 Months and Longer (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 35,969	$ 124,418
Less Than 12 Months, Unrealized Losses	150	412
12 Months or Longer, Fair Value	65,325	51,751
12 Months or Longer, Unrealized Losses	520	284
Total, Fair Value	101,294	176,169
Total, Unrealized Losses	670	696
SBA Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	13,839	14,560
Less Than 12 Months, Unrealized Losses	42	30
12 Months or Longer, Fair Value	30,200	22,092
12 Months or Longer, Unrealized Losses	247	113
Total, Fair Value	44,039	36,652
Total, Unrealized Losses	289	143
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	18,188	108,806
Less Than 12 Months, Unrealized Losses	50	379
12 Months or Longer, Fair Value	33,617	29,178
12 Months or Longer, Unrealized Losses	267	153
Total, Fair Value	51,805	137,984
Total, Unrealized Losses	317	532
Privately Issued Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value		252
Less Than 12 Months, Unrealized Losses		2
12 Months or Longer, Fair Value	210
12 Months or Longer, Unrealized Losses	4
Total, Fair Value	210	252
Total, Unrealized Losses	4	2
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	3,942	800
Less Than 12 Months, Unrealized Losses	58	1
12 Months or Longer, Fair Value	1,298	481
12 Months or Longer, Unrealized Losses	2	18
Total, Fair Value	5,240	1,281
Total, Unrealized Losses	$ 60	$ 19