Investment Securities - Schedule of Amortized Cost and Approximate Fair Value of Investment Securities Classified as Available for Sale (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 77,765	$ 56,733
Gross Unrealized Gains	385	257
Gross Unrealized Losses	(311)	(817)
Fair Value	77,839	56,173
Obligations of other U.S. government agencies and corporations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,285	2,227
Gross Unrealized Gains	36	26
Gross Unrealized Losses	(26)	(43)
Fair Value	3,295	2,210
Mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	57,212	34,478
Gross Unrealized Gains	183	204
Gross Unrealized Losses	(159)	(220)
Fair Value	57,236	34,462
Obligations of state and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,346	14,581
Gross Unrealized Gains	136	14
Gross Unrealized Losses	(85)	(495)
Fair Value	11,397	14,100
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,416	4,941
Gross Unrealized Gains	30	13
Gross Unrealized Losses	(19)	(29)
Fair Value	5,427	4,925
Equity mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	506	506
Gross Unrealized Losses	(22)	(30)
Fair Value	$ 484	$ 476