Loans Troubled Debt Restructurings (Details) $ in Millions	3 Months Ended
Mar. 31, 2016 USD ($) contracts	Mar. 31, 2015 USD ($) contracts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts \| contracts	113	129
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default \| $	$ 7	$ 8
Commercial and Industrial Sector [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts \| contracts	5	4
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default \| $	$ 1	$ 1
Residential Nonguaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts \| contracts	19	36
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default \| $	$ 5	$ 6
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts \| contracts	38	30
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default \| $	$ 1	$ 1
Consumer Other Direct [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts \| contracts		1
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default \| $		$ 0
Consumer Indirect [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts \| contracts	29	39
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default \| $	$ 0	$ 0
Credit Card Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Restructured, Payment Default During Peiriod, Number of Contracts \| contracts	22	19
Financing Receivable, Restructured, Payment Default During Period, Amortized Cost at Default \| $	$ 0	$ 0

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953682-111524

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Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

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