| **Preferred and Common Stock**            | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            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| **Preferred and Common Stock [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            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| Preferred and Common Stock                | Note 14. Preferred and Common StockPreferred StockOn January 9, 2009, the Company issued $25 million in Fixed Rate Cumulative Perpetual Preferred Stock, Series A, having a liquidation preference of $1,000 per share, to the U.S. Treasury under the Capital Purchase Program ("the CPP Shares"). The CPP Shares call for cumulative dividends at a rate of 5.0% per year for the first five years, and at a rate of 9.0% per year in following years, payable quarterly in arrears on February 15, May 15, August 15 and November 15 of each year.On August 24, 2011, the Company repurchased $12.5 million of the CPP Shares. The repurchase transaction was approved by the Federal Reserve Bank of Boston, the Company's primary regulator, as well as the Bank's primary regulator, the Office of the Comptroller of the Currency, based on continued strong capital ratios after the repayment. Almost all of the repayment was made from retained earnings accumulated since the preferred stock was issued in 2009. After the repurchase, $12.5 million of the CPP shares remains outstanding. The Company may redeem the remaining CPP Shares at any time using any funds available, subject to the prior approval of the Federal Reserve Bank of Boston. The CPP Shares are "perpetual" preferred stock, which means that neither Treasury nor any subsequent holder would have a right to require that the Company redeem any of the shares.Incident to such issuance, the Company issued to the U.S. Treasury warrants (the "Warrants") to purchase up to 225,904 shares of the Company's common stock at a price per share of $16.60 (subject to adjustment). The CPP Shares and the related Warrants (and any shares of common stock issuable pursuant to the Warrants) are freely transferable by Treasury to third parties and the Company has filed a registration statement with the Securities and Exchange Commission to allow for possible resale of such securities. The CPP Shares qualify as Tier 1 capital on the Company's books for regulatory purposes and rank senior to the Company's common stock and senior or at an equal level in the Company's capital structure to any other shares of preferred stock the Company may issue in the future.The Warrants issued in conjunction with the sale of the CPP Shares have a term of ten years and could be exercised by Treasury or a subsequent holder at any time or from time to time during their term. To the extent they had not previously been exercised, the Warrants would expire after ten years. Treasury will not vote any shares of common stock it receives upon exercise of the Warrants, but that restriction would not apply to third parties to whom Treasury transferred the Warrants. The Warrants (and any common stock issued upon exercise of the Warrants) could be transferred to third parties separately from the CPP Shares. The proceeds from the sale of the CPP Shares were allocated between the CPP Shares and Warrants based on their relative fair values on the issue date. The fair value of the Warrants was determined using the Black-Scholes model which includes the following assumptions: common stock price of $16.60 per share, dividend yield of 4.70%, stock price volatility of 24.43%, and a risk-free interest rate of 2.01%. The discount on the CPP Shares was based on the value that was allocated to the Warrants upon issuance, and is being accreted back to the value of the CPP Shares over a five-year period (the expected life of the shares upon issuance) on a straight-line basis. The Warrants were unchanged as a result of the CPP Shares repurchase transaction and remain outstanding.As a condition to Treasury's purchase of the CPP Shares, during the time that Treasury holds any equity or debt instrument the Company issued, the Company is required to comply with certain restrictions and other requirements relating to the compensation of the Company's chief executive officer, chief financial officer and three other most highly compensated executive officers. These restrictions include a prohibition on severance payments to those executive officers upon termination of their employment and a $500,000 limit on the tax deductions the Company can take for compensation expense for each of those executive officers in a single year as well as a prohibition on bonus compensation to such officers other than limited amounts of long-term restricted stock.Common StockThe Company has reserved 700,000 shares of its common stock to be made available to directors and employees who elect to participate in the stock purchase or savings and investment plans. During 2006, the number of shares set aside for these plans was increased by the Board of Directors from 480,000 to 700,000. As of December 31, 2012, 522,411 shares had been issued pursuant to these plans, leaving 177,589 shares available for future use. The issuance price is based on the market price of the stock at issuance date. Sales of stock to directors and employees amounted to 12,451 shares in 2012, 12,775 shares in 2011, and 12,334 shares in 2010.In 2001, the Company established a dividend reinvestment plan to allow shareholders to use their cash dividends for the automatic purchase of shares in the Company. When the plan was established, 600,000 shares were registered with the Securities and Exchange Commission, and as of December 31, 2012, 200,580 shares have been issued, leaving 399,420 shares for future use. Participation in this plan is optional and at the individual discretion of each Shareholder. Shares are purchased for the plan from the Company at a price per share equal to the average of the daily bid and asked prices reported on the NASDAQ System for the five trading days immediately preceding, but not including, the dividend payment date. Sales of stock under the Dividend Reinvestment Plan amounted to 14,056 shares in 2012, 14,387 shares in 2011, and 16,520 shares in 2010. |

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| - Definition
The entire disclosure for shareholders' equity, comprised of portions attributable to the parent entity and noncontrolling interest, if any, including other comprehensive income (as applicable).  Including, but not limited to: (1) balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings; (2) accumulated balance for each classification of other comprehensive income and total amount of comprehensive income; (3) amount and nature of changes in separate accounts, including the number of shares authorized and outstanding, number of shares issued upon exercise and conversion, and for other comprehensive income, the adjustments for reclassifications to net income; (4) rights and privileges of each class of stock authorized; (5) basis of treasury stock, if other than cost, and amounts paid and accounting treatment for treasury stock purchased significantly in excess of market; (6) dividends paid or payable per share and in the aggregate for each class of stock for each period presented; (7) dividend restrictions and accumulated preferred dividends in arrears (in aggregate and per share amount); (8) retained earnings appropriations or restrictions, such as dividend restrictions; (9) impact of change in accounting principle, initial adoption of new accounting principle and correction of an error in previously issued financial statements; (10) shares held in trust for Employee Stock Ownership Plan (ESOP); (11) deferred compensation related to issuance of capital stock; (12) note received for issuance of stock; (13) unamortized discount on shares; (14) description, terms, and number of warrants or rights outstanding; (15) shares under subscription and subscription receivables, effective date of new retained earnings after quasi-reorganization and deficit eliminated by quasi-reorganization and, for a period of at least ten years after the effective date, the point in time from which the new retained dates; and (16) retroactive effective of subsequent change in capital structure.
+ References
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