Loans, Additional Information (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Pledged financial instruments, securities for federal home loan bank	$ 232	$ 212
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Home equity line of credit draw period	5 years
Minimum [Member] \| Commercial Secured By Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortization period	5 years
Balloon payments period	1 year
Adjustable rate period	1 year
Minimum [Member] \| Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortization period	5 years
Loan to appraised value ratio	80.00%
Maximum [Member] \| Commercial Secured By Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortization period	25 years
Balloon payments period	10 years
Adjustable rate period	10 years
Loan to appraised value ratio	75.00%
Maximum [Member] \| Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortization period	30 years
Maximum [Member] \| Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortization period	72 months

Financing Receivable, Amortization Period

No definition available.

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- Definition

Financing Receivable, Line of Credit Draw Period

+ References

No definition available.

+ Details

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- Definition

Financing Receivable, Periodic Payment Terms, Balloon Payment Period

+ References

No definition available.

+ Details

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- Definition

Financing Receivable, Variable Rates of Interest, Adjustment Period

+ References

No definition available.

+ Details

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- Definition

Loan and Lease Receivable, Ratio of Loan to Appraised Value

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

The carrying amount as of the date of the latest financial statement presented of securities which are owned but transferred to serve as collateral for FHLB debt obligations, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 30

-Section 50

-Paragraph 1A

-Subparagraph (b)(1)(i)

-URI http://asc.fasb.org/extlink&oid=55761124&loc=SL6224234-111729

+ Details

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Period Type:	instant

- Details

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- Details

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