Securities Sold Under Agreements to Repurchase and Other Short-Term Debt (Narrative) (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Securities Sold Under Agreements to Repurchase and Other Short-Term Debt [Abstract]
Carrying value of securities sold under agreements to repurchase	$ 287,520,000	$ 262,527,000
Borrowing capacity through unsecured borrowing lines	45,000,000
Loans pledged to the FHLB	342,560,000	225,860,000
Additional short or long-term borrowing capacity with FHLBB	$ 232,340,000