Estimated Fair Value of Financial Instruments - Balances of Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Fair Value Of Other Financial Instrument [Line Items]
Impaired and nonaccrual loans	$ 18,207	$ 21,986
Other real estate	979	579
Total assets at fair value on a nonrecurring basis	19,186	22,565
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Of Other Financial Instrument [Line Items]
Impaired and nonaccrual loans	0	0
Other real estate	0	0
Total assets at fair value on a nonrecurring basis	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Of Other Financial Instrument [Line Items]
Impaired and nonaccrual loans	0	0
Other real estate	0	0
Total assets at fair value on a nonrecurring basis	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Of Other Financial Instrument [Line Items]
Impaired and nonaccrual loans	18,207	21,986
Other real estate	979	579
Total assets at fair value on a nonrecurring basis	$ 19,186	$ 22,565