Fair Value Measurements Fair Value of Assets and Liabilities on Recurring And Nonrecurring Basis (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Dec. 31, 2010
Assets and liabilities measured on recurring and nonrecurring basis [Line Items]
Goodwill implied fair value		$ 782
Debt Instrument, Fair Value Disclosure	4,760		4,649
Goodwill, Impairment Loss		697
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Time Deposits, at Carrying Value	66		88
Accrued Contingent Consideration	365		358
Cash	116		101
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Cost-method Investments, Aggregate Carrying Amount	13		16
Carrying value of goodwill prior to impairment				1,479
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Money Market Funds, at Carrying Value
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Money Market Funds, at Carrying Value	102		78
Foreign Currency Contract, Asset, Fair Value Disclosure	74		87
Assets, Fair Value Disclosure	176		165
Currency Hedge Contracts Liabilities	79		131
Accrued Contingent Consideration	365		358
Liabilities, Fair Value Disclosure	444		489
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Money Market Funds, at Carrying Value	102		78
Foreign Currency Contract, Asset, Fair Value Disclosure
Assets, Fair Value Disclosure	102		78
Currency Hedge Contracts Liabilities
Accrued Contingent Consideration
Liabilities, Fair Value Disclosure
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Money Market Funds, at Carrying Value
Foreign Currency Contract, Asset, Fair Value Disclosure	74		87
Assets, Fair Value Disclosure	74		87
Currency Hedge Contracts Liabilities	79		131
Accrued Contingent Consideration
Liabilities, Fair Value Disclosure	79		131
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Money Market Funds, at Carrying Value
Foreign Currency Contract, Asset, Fair Value Disclosure
Assets, Fair Value Disclosure
Currency Hedge Contracts Liabilities
Accrued Contingent Consideration	365		358
Liabilities, Fair Value Disclosure	$ 365		$ 358