Estimated Fair Value of Financial Instruments - Additional Information (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	$ 0
Impaired loans, valuation allowance	514,000	917,000	1,016,000
Collateral Dependent Loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired loans, principal balance	777,000	5,924,000
Impaired loans, valuation allowance	186,000	1,546,000
Impaired loans, reduction in loan losses	$ 124,000	$ 127,000