Borrowings (Federal Home Loan Bank Advances Maturity Schedule) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 288,485	$ 361,172
Federal Home Loan Bank of Boston [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Scheduled maturity due in year one	403	48,630
Redeemed at call date due in year one	403	48,630
Weighted average rate in year one	5.01%	0.81%
Scheduled maturity due in year two	2,519	2,519
Redeemed at call date due from one to two years	2,519	2,519
Weigted average rate from one to two years	3.54%	3.54%
Scheduled maturity due in year three	1,569	79,069
Redeemed at call date due from two to thee years	1,569	79,069
Weighted average rate from two to three years	4.89%	3.63%
Scheduled maturity due in year four	85,066	85,066
Redeemed at call date due from three to four years	85,066	85,066
Weighted average rate from three to four years	3.05%	3.05%
Scheduled maturities due in year five	70,875	80,335
Redeemed at call date due from four to five years	70,875	80,335
Weighted average rate from four to five years	3.04%	2.94%
Scheduled maturity due after year five	128,053	65,553
Redeemed at call date due after five years	128,053	65,553
Weighted average rate after five years	3.88%	4.58%
Federal Home Loan Bank advances	288,485	361,172
Total redemption at call date	$ 288,485	$ 361,172
Total weighted average rate	3.43%	3.13%