Estimated Fair Value of Financial Instruments - Assets Measured by Fair Value on a Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	$ 216,122	$ 203,763
Estimated Fair Value [Member]
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	216,344	203,763
Estimated Fair Value [Member] | U.S. Government agencies and corporations
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	65,388	36,970
Estimated Fair Value [Member] | Mortgage backed securities
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	94,430	111,701
Estimated Fair Value [Member] | Collateralized mortgage obligations
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	18,655	22,881
Estimated Fair Value [Member] | Preferred securities
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	4,684
Estimated Fair Value [Member] | State and political subdivisions
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	32,965	32,211
Estimated Fair Value [Member] | Interest rate swaps
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	222
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Government agencies and corporations
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage backed securities
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Collateralized mortgage obligations
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | State and political subdivisions
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest rate swaps
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	211,660	203,763
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government agencies and corporations
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	65,388
Significant Other Observable Inputs (Level 2) [Member] | Mortgage backed securities
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	94,430
Significant Other Observable Inputs (Level 2) [Member] | Collateralized mortgage obligations
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	18,655
Significant Other Observable Inputs (Level 2) [Member] | State and political subdivisions
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	32,965
Significant Other Observable Inputs (Level 2) [Member] | Interest rate swaps
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	222
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	4,684	0
Significant Unobservable Inputs (Level 3) [Member] | U.S. Government agencies and corporations
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Mortgage backed securities
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Collateralized mortgage obligations
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Preferred securities
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	4,684
Significant Unobservable Inputs (Level 3) [Member] | State and political subdivisions
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Interest rate swaps
Fair Value Of Other Financial Instrument [Line Items]
Securities available for sale, at fair value	$ 0