Securities Available-for-Sale - Continuous Unrealized Loss Position for 12 Months or Less and 12 Months and Longer (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 124,418	$ 41,108
Less Than 12 Months, Unrealized Losses	412	80
12 Months or Longer, Fair Value	51,751	93,047
12 Months or Longer, Unrealized Losses	284	547
Total, Fair Value	176,169	134,155
Total, Unrealized Losses	696	627
U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or Longer, Fair Value		1,992
12 Months or Longer, Unrealized Losses		8
Total, Fair Value		1,992
Total, Unrealized Losses		8
U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value		3,914
Less Than 12 Months, Unrealized Losses		31
Total, Fair Value		3,914
Total, Unrealized Losses		31
SBA Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	14,560	17,950
Less Than 12 Months, Unrealized Losses	30	28
12 Months or Longer, Fair Value	22,092	44,323
12 Months or Longer, Unrealized Losses	113	256
Total, Fair Value	36,652	62,273
Total, Unrealized Losses	143	284
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	108,806	19,244
Less Than 12 Months, Unrealized Losses	379	21
12 Months or Longer, Fair Value	29,178	45,782
12 Months or Longer, Unrealized Losses	153	229
Total, Fair Value	137,984	65,026
Total, Unrealized Losses	532	250
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		495
12 Months or Longer, Unrealized Losses		10
Total, Fair Value	252	495
Total, Unrealized Losses	2	10
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	800
Less Than 12 Months, Unrealized Losses	1
12 Months or Longer, Fair Value	481	455
12 Months or Longer, Unrealized Losses	18	44
Total, Fair Value	1,281	455
Total, Unrealized Losses	$ 19	$ 44