Mortgage Servicing Rights and Mortgage Servicing Activity (Details Textual) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Servicing Assets at Fair Value [Line Items]
Principal Amount Outstanding of Loans Held-in-portfolio	$ 356,500,000	$ 562,300,000
Mortgage Servicing rights Valuation Allowance	(955,000)	282,000	2,564,000	3,539,000
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale, Gain (Loss) on Sale	7,200,000	12,100,000
Qualitative and Quantitative Information, Transferor's Continuing Involvement, Principal Amount Outstanding, Continued Recognition, Amount	314,400,000	514,600,000
Minimum percentage adverse change in prepayment speed	10.00%
Maximum percentage adverse change in prepayment speed	25.00%
Percentage of variation in prepayment speed	10.00%
Residential Mortgage
Servicing Assets at Fair Value [Line Items]
Servicing Asset	2,600,000,000	2,700,000,000
Contractually Specified Servicing Fees, Amount	$ 6,600,000	$ 6,400,000	$ 5,800,000

Maximum percentage adverse change in prepayment speed.

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- Definition

Minimum percentage adverse change in prepayment speed.

+ References

No definition available.

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- Definition

Mortgage Servicing rights Valuation Allowance

+ References

No definition available.

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- Definition

Percentage of variation in prepayment speed.

+ References

No definition available.

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- Definition

All amounts that, per contract, are due to the servicer in exchange for servicing the financial asset and would no longer be received by a servicer if the beneficial owners of the serviced assets (or their trustees or agents) were to exercise their actual or potential authority under the contract to shift the servicing to another servicer. Depending on the servicing contract, those fees may include some or all of the difference between the interest rate collected on the asset being serviced and the rate to be paid to the beneficial owners of the asset.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=7882072&loc=d3e122596-111746

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- Definition

This is the result of the principal amount outstanding of total loans managed or securitized less securitized loans and loans that are in the process of being securitized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107314-111719

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- Definition

Reflects, by transferred financial asset type, the amount of sales proceeds in excess of or deficient from the sum of the carrying amounts of transferred financial assets plus transaction costs, including those transactions in which the seller/transferor has continuing involvement with the financial assets that have been transferred.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107207-111719

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 10

-Section 40

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=45353237&loc=d3e96813-111708

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- Definition

Amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction that continue to be recognized in the statement of financial position. Includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107314-111719

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- Definition

Aggregate amount of servicing assets that are subsequently measured at fair value and servicing assets that are subsequently measured using the amortization method.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745

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