Securities Available-for-Sale - Summary of Securities Available-for-Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 291,699	$ 336,751
Gross Unrealized Gains	431	635
Gross Unrealized Losses	728	627
Total, Fair Value	291,402	336,759
U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		2,000
Gross Unrealized Losses		8
Total, Fair Value		1,992
U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,954	3,946
Gross Unrealized Gains	20
Gross Unrealized Losses		31
Total, Fair Value	3,974	3,915
SBA Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	64,970	70,477
Gross Unrealized Gains	96	1
Gross Unrealized Losses	54	284
Total, Fair Value	65,012	70,194
U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	176,607	162,604
Gross Unrealized Gains	187	536
Gross Unrealized Losses	639	250
Total, Fair Value	176,155	162,890
Privately Issued Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	622	679
Gross Unrealized Gains	7	3
Gross Unrealized Losses	2	10
Total, Fair Value	627	672
Obligations Issued by States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	41,946	93,445
Gross Unrealized Gains	56	58
Total, Fair Value	42,002	93,503
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,600	3,600
Gross Unrealized Gains	65	37
Gross Unrealized Losses	33	44
Total, Fair Value	$ 3,632	$ 3,593