Securities Available-for-Sale - Continuous Unrealized Loss Position for 12 Months or Less and 12 Months and Longer (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 41,108	$ 61,156
Less Than 12 Months, Unrealized Losses	80	193
12 Months or Longer, Fair Value	93,047	105,799
12 Months or Longer, Unrealized Losses	547	597
Total, Fair Value	134,155	166,955
Total, Unrealized Losses	627	790
U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value		1,984
Less Than 12 Months, Unrealized Losses		15
12 Months or Longer, Fair Value	1,992
12 Months or Longer, Unrealized Losses	8
Total, Fair Value	1,992	1,984
Total, Unrealized Losses	8	15
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	17,950	18,378
Less Than 12 Months, Unrealized Losses	28	54
12 Months or Longer, Fair Value	44,323	40,911
12 Months or Longer, Unrealized Losses	256	107
Total, Fair Value	62,273	59,289
Total, Unrealized Losses	284	161
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	19,244	40,394
Less Than 12 Months, Unrealized Losses	21	123
12 Months or Longer, Fair Value	45,782	59,336
12 Months or Longer, Unrealized Losses	229	194
Total, Fair Value	65,026	99,730
Total, Unrealized Losses	250	317
Privately Issued Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or Longer, Fair Value	495	633
12 Months or Longer, Unrealized Losses	10	9
Total, Fair Value	495	633
Total, Unrealized Losses	10	9
Obligations Issued by States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or Longer, Fair Value		4,458
12 Months or Longer, Unrealized Losses		249
Total, Fair Value		4,458
Total, Unrealized Losses		249
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value		400
Less Than 12 Months, Unrealized Losses		1
12 Months or Longer, Fair Value	455	461
12 Months or Longer, Unrealized Losses	44	38
Total, Fair Value	455	861
Total, Unrealized Losses	$ 44	$ 39