Derivatives and Hedging Activities (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Fair value hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) on Derivatives	$ (4)	$ 37
Net Gains (Losses) on Hedged Item	46	7
Cash flow hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) Recognized in OCI (Effective Portion)	29	2
Net Gains (Losses) Reclassified From OCI Into Income (Effective Portion)	11	14
Net Gains (Losses) Recognized in Income (Ineffective Portion)	0
Interest rate [Member] \| Cash flow hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) Recognized in OCI (Effective Portion)	0
Other Income [Member] \| Cash flow hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) Reclassified From OCI Into Income (Effective Portion)	0
Net Gains (Losses) Recognized in Income (Ineffective Portion)	0
Other Income [Member] \| Interest rate [Member] \| Fair value hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) on Derivatives	(55)	(84)
Net Gains (Losses) on Hedged Item	52	80
Other Income [Member] \| Foreign exchange [Member] \| Fair value hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) on Derivatives	5	65
Net Gains (Losses) on Hedged Item	(5)	(69)
Interest Expense [Member] \| Cash flow hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) Reclassified From OCI Into Income (Effective Portion)	(2)	(3)
Interest Expense [Member] \| Interest rate [Member] \| Fair value hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) on Derivatives	45	54
Interest Expense [Member] \| Interest rate [Member] \| Cash flow hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) Recognized in OCI (Effective Portion)	6	3
Interest Expense [Member] \| Foreign exchange [Member] \| Fair value hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) on Derivatives	1	2
Net Gains (Losses) on Hedged Item	(1)	(4)
Interest Income [Member] \| Cash flow hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) Reclassified From OCI Into Income (Effective Portion)	13	17
Interest Income [Member] \| Interest rate [Member] \| Cash flow hedges [Member]
Pre-tax net gains (losses) on fair value hedges
Net Gains (Losses) Recognized in OCI (Effective Portion)	$ 23	$ (1)

Amount of the increase or decrease in fair value during the period of derivative or nonderivative instruments designated as fair value hedging instruments. Recognized in earnings and offsets the gain (loss) on the hedged item to the extent that the fair value hedge is determined to be effective.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 45

-Subparagraph a(1)

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- Definition

Amount of the increase or decrease in fair value during the period of the hedged item in a fair value hedge. Recognized in earnings and is offset by the gain (loss) on the hedging instrument to the extent that the fair value hedge is determined to be effective.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 45

-Subparagraph a(1)

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- Definition

The income statement location of the effective portion of net gain or loss reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 205G

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44C

-Subparagraph b

-Clause 3

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- Definition

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

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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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