Borrowings (Narrative Federal Home Loan Bank Advances) (Details) (USD $)	3 Months Ended
Mar. 31, 2014	Mar. 03, 2014	Dec. 31, 2013
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 203,429,000		$ 288,082,000
Federal Home Loan Bank advances, amount of advances prepaid		99,300,000
Federal Home Loan Bank advances, prepayment penalty charge	6,300,000
Federal Home Loan Bank advances, prepaid weighted average rate	3.01%
FHLB Advances Prepaid Remaining Months	36 months
Federal Home Loan Bank of Boston [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank advances	203,429,000		288,082,000
Unused line of credit with FHLB	20,000,000
Unused line of credit with FHLB	$ 654,700,000		$ 564,100,000

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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- Details

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- Definition

Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.13(3)(a))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22 (b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 13

-Subparagraph 3(a)

-Article 9

+ Details

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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- Definition

Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances Prepaid

+ References

No definition available.

+ Details

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- Definition

Federal Home Loan Bank, Advances, Branch of FHLB Bank, Prepayment Penalty Charge

+ References

No definition available.

+ Details

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- Definition

Remaining average term on prepaid FHLB advances.

+ References

No definition available.

+ Details

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- Definition

The weighted average rate on FHLB advances that were prepaid during the period.

+ References

No definition available.

+ Details

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