Derivative Instruments and Hedging Activities (Gains or Losses on Derivative Instruments, Related Hedge Items and Hedge Ineffectiveness) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Designated as Accounting Hedges \| Interest Expense
Derivatives
Gains (Losses) on Fair Value Hedges Recognized	$ (139.0)	$ (85.0)
Designated as Accounting Hedges \| Interest Expense \| Derivatives
Derivatives
Gains (Losses) on Fair Value Hedges Recognized	2,150.0	758.0
Designated as Accounting Hedges \| Interest Expense \| Borrowings
Derivatives
Gains (Losses) on Fair Value Hedges Recognized	(2,289.0)	(843.0)
Not Designated as Accounting Hedges
Derivatives
Gains (Losses) Recognized in Income	2,065.0	3,525.0
Debt valuation adjustment	0.0	125.0
Total	2,065.0	3,650.0
Not Designated as Accounting Hedges \| Interest Rate Contracts
Derivatives
Gains (Losses) Recognized in Income	306.0	570.0
Not Designated as Accounting Hedges \| Foreign Exchange Contracts
Derivatives
Gains (Losses) Recognized in Income	237.0	345.0
Not Designated as Accounting Hedges \| Equity security and index contracts
Derivatives
Gains (Losses) Recognized in Income	1,330.0	1,595.0
Not Designated as Accounting Hedges \| Commodity and other contracts
Derivatives
Gains (Losses) Recognized in Income	(144.0)	676.0
Not Designated as Accounting Hedges \| Credit Contracts
Derivatives
Gains (Losses) Recognized in Income	336.0	339.0
Net Investment Hedges \| Designated as Accounting Hedges \| Foreign Exchange Contracts
Derivatives
Gain (Losses) Recognized in OCI (effective portion)	(224.0)	262.0
Gain (loss) recognized in interest income related to amounts excluded from hedge effectiveness testing	$ (20.0)	$ (44.0)

Debt valuation adjustment due to accounting updates.

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5618551-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (a),(c),(d),(e)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624171-113959

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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.

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No definition available.

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The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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Aggregate net gain and losses (whether realized or unrealized) on all derivative instruments held for trading purposes whether or not settled physically.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41322-113958

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Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period.

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