Debt (Narrative) (Details) (USD $)	0 Months Ended	12 Months Ended
Jul. 12, 2011	Dec. 31, 2011
Debt Instrument [Line Items]
Aggregate principal amount of fixed-rate notes		$ 3,900,000,000
Percentage of owned subsidiaries guaranteed fixed-rate notes		100.00%
Percentage of option to redeem notes prior to maturity in whole or in part		100.00%
Issuance of fixed-rate notes	1,500,000,000
Fixed-rate notes, payable in increments	500,000,000
Repayments of fixed-rate note on maturity	750,000,000
Multi-Year Facility Expiring July 2013 [Member]
Debt Instrument [Line Items]
Line of credit facility, expiration date		July 2013
Multi-Year Facility, Expiring July 2016 [Member]
Debt Instrument [Line Items]
Line of credit facility, expiration date		July 2016
Commercial Paper [Member]
Debt Instrument [Line Items]
Percentage of owned subsidiaries guaranteed fixed-rate notes		100.00%
Credit facilities		2,000,000,000
Commercial Paper [Member] \| Multi-Year Facility Expiring July 2013 [Member]
Debt Instrument [Line Items]
Credit facilities		1,000,000,000
Commercial Paper [Member] \| Multi-Year Facility, Expiring July 2016 [Member]
Debt Instrument [Line Items]
Credit facilities		$ 1,000,000,000

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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The cash outflow attributable to repayments of borrowings not otherwise defined in the taxonomy (with maturities initially due after one year or beyond the operating cycle if longer).

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