Disclosures About Fair Value of Financial Instruments - Estimated fair values of Corporation's financial instruments and level within fair value hierarchy (Unaudited) (Details 4) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Assets
Investment securities available for sale	$ 126,308	$ 113,770
Carrying Amount
Assets
Cash and cash equivalents	19,827	19,152
Investment securities available for sale	126,308	113,770
Loans, held for sale	355	394
Loans, net of allowance for losses	294,366	305,518
Federal Home Loan Bank stock	4,595	4,595
Interest receivable	2,053	2,292
Liabilities
Deposits	388,618	384,255
Borrowings	49,717	49,717
Interest payable	319	362
Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Cash and cash equivalents	19,827	19,152
Investment securities available for sale
Loans, held for sale
Loans, net of allowance for losses
Federal Home Loan Bank stock
Interest receivable
Liabilities
Deposits
Borrowings
Interest payable
Fair Value Measurements Using Significant Other Observable Inputs (Level 2)
Assets
Cash and cash equivalents
Investment securities available for sale	125,087	112,573
Loans, held for sale	355	394
Loans, net of allowance for losses	317,864	331,543
Federal Home Loan Bank stock	4,595	4,595
Interest receivable	2,053	2,292
Liabilities
Deposits	389,795	386,068
Borrowings	45,025	45,849
Interest payable	319	362
Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
Assets
Cash and cash equivalents
Investment securities available for sale	1,221	1,197
Loans, held for sale
Loans, net of allowance for losses
Federal Home Loan Bank stock
Interest receivable
Liabilities
Deposits
Borrowings	7,217	6,898
Interest payable