Estimated Fair Value of Financial Instruments - Assets Measured by Fair Value on a Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fair Value [Member]
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	$ 204,128	$ 217,724
U.S. Government agencies and corporations
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	46,194
U.S. Government agencies and corporations | Fair Value [Member]
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	46,194	60,762
Mortgage backed securities: residential
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	91,312
Mortgage backed securities: residential | Fair Value [Member]
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	91,312	93,220
Residential collateralized mortgage obligations
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	32,125
Residential collateralized mortgage obligations | Fair Value [Member]
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	32,125	28,535
State and political subdivisions
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	34,217
State and political subdivisions | Fair Value [Member]
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	34,217	35,055
Derivative interest rate swaps | Fair Value [Member]
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	280	152
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	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]
Assets, Fair Value Disclosure, Recurring	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage backed securities: residential
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Residential collateralized mortgage obligations
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	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]
Assets, Fair Value Disclosure, Recurring	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Derivative interest rate swaps
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	204,128	217,724
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government agencies and corporations
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	46,194	60,762
Significant Other Observable Inputs (Level 2) [Member] | Mortgage backed securities: residential
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	91,312	93,220
Significant Other Observable Inputs (Level 2) [Member] | Residential collateralized mortgage obligations
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	32,125	28,535
Significant Other Observable Inputs (Level 2) [Member] | State and political subdivisions
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	34,217	35,055
Significant Other Observable Inputs (Level 2) [Member] | Derivative interest rate swaps
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	280	152
Significant Unobservable Inputs (Level 3) [Member] | U.S. Government agencies and corporations
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Significant Unobservable Inputs (Level 3) [Member] | Mortgage backed securities: residential
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Significant Unobservable Inputs (Level 3) [Member] | Residential collateralized mortgage obligations
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Significant Unobservable Inputs (Level 3) [Member] | State and political subdivisions
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Significant Unobservable Inputs (Level 3) [Member] | Derivative interest rate swaps
Fair Value Of Other Financial Instrument [Line Items]
Assets, Fair Value Disclosure, Recurring	$ 0	$ 0