Pledged Assets (Details) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2012
Dec. 31, 2011
Securities and loans pledged to secure securities sold under agreements to repurchase, FHLBB advances and credit facilities available    
Securities held-to-maturity (at cost) $ 34,321 $ 41,165
Loans receivable 222,215 176,574
Total pledged assets 256,536 217,739
Repurchase agreements [Member]
    
Securities and loans pledged to secure securities sold under agreements to repurchase, FHLBB advances and credit facilities available    
Securities held-to-maturity (at cost) 4,752 5,715
Total pledged assets 4,752 5,715
FHLBB borrowings [Member]
    
Securities and loans pledged to secure securities sold under agreements to repurchase, FHLBB advances and credit facilities available    
Securities held-to-maturity (at cost) 16,367 25,098
Loans receivable 222,215 176,574
Total pledged assets 238,582 201,672
Federal Reserve Bank LOC [Member]
    
Securities and loans pledged to secure securities sold under agreements to repurchase, FHLBB advances and credit facilities available    
Securities held-to-maturity (at cost) 13,202 10,352
Total pledged assets $ 13,202 $ 10,352