Investment Securities Available-for-Sale - Summary of Amortized Cost and Estimated Fair Values of Investment Securities Available-for-Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 72,799	$ 75,151
Gross Unrealized Gains	1,561	815
Gross Unrealized Losses	107	116
Fair Value	74,253	75,850
U.S. Treasuries [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		103
Fair Value		103
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,202	4,708
Gross Unrealized Gains	61	29
Fair Value	2,263	4,737
State and Municipal [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	44,264	34,197
Gross Unrealized Gains	933	587
Gross Unrealized Losses	14	14
Fair Value	45,183	34,770
Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	16,100	25,942
Gross Unrealized Gains	273	116
Gross Unrealized Losses		35
Fair Value	16,373	26,023
Collateralized Mortgage Obligations (CMOs) [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,741
Gross Unrealized Gains		35
Gross Unrealized Losses		3
Fair Value		1,773
Corporate Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,040	7,989
Gross Unrealized Gains	262	17
Gross Unrealized Losses	48	62
Fair Value	10,254	7,945
Equity Securities, Financial Services [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	193	471
Gross Unrealized Gains	32	31
Gross Unrealized Losses	45	2
Fair Value	$ 180	$ 499