Derivative Financial Instruments and Risk Management (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss)
Interest rate contracts, Amount of Gains (Losses) Reclassified from AOCI to Earnings (Effective Portion)	$ 4	$ (12)	$ (49)
Interest rate contracts, Recognized in Earnings (Ineffective Portion)	(1)	(2)	(1)
Gains (Losses) on derivatives not designated as hedging instruments	6	(15)	18
Interest expense
Derivative Instruments, Gain (Loss)
Interest rate contracts, Amount of Gains (Losses) Reclassified from AOCI to Earnings (Effective Portion)	4	(12)	(49)
Interest rate contracts, Recognized in Earnings (Ineffective Portion)	0	0	0
Other income (expense)
Derivative Instruments, Gain (Loss)
Gains (Losses) on Derivatives	(20)	39	107
Gains (Losses) on Borrowings	36	(44)	(98)
Interest rate contracts, Amount of Gains (Losses) Reclassified from AOCI to Earnings (Effective Portion)	0	0	0
Interest rate contracts, Recognized in Earnings (Ineffective Portion)	(1)	(2)	(1)
Interest rate contracts, Gains (Losses) on derivatives not designated as hedging instruments	0	0	2
Foreign exchange contracts \| Other income (expense)
Derivative Instruments, Gain (Loss)
Foreign exchange contracts, Gains (Losses) on derivatives not designated as hedging instruments	7	(15)	16
Cross currency contracts \| Other income (expense)
Derivative Instruments, Gain (Loss)
Foreign exchange contracts, Gains (Losses) on derivatives not designated as hedging instruments	$ (1)	$ 0	$ 0

The amount of net gains or losses on a cash flow hedge reclassified in the period to earnings from accumulated other comprehensive income.

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

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-Name Accounting Standards Codification

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Net gain (loss) from the increase (decrease) in fair value of derivative instrument not designated as hedging instrument.

+ References

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Amount of gain (loss) recognized in earnings in the period from the increase (decrease) in fair value of foreign currency derivatives not designated as hedging instruments.

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Amount of gain (loss) included in earnings for the period from the increase (decrease) in fair value of interest rate derivatives not designated as hedging instruments.

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Amount of unrealized gain (loss) included in earnings related to the fair value of the hedged item in an interest rate fair value hedge, offset by the gain (loss) on the hedging instrument to the extent that the fair value hedge is determined to be effective.

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Amount of unrealized gain (loss) related to the fair value of interest rate derivatives designated as fair value hedging instruments, as offset by the gain (loss) on the hedged item to the extent that the fair value hedge is determined to be effective.

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Amount of unrealized gain (loss) related to derivatives designated as cash flow hedging instruments, recorded in results of operations to the extent that the cash flow hedge is determined to be ineffective.

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