Debt (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Line of Credit Facility [Line Items]
Amortization of Purchase Accounting Premium	$ 9,000,000	$ 26,000,000
Deferred Finance Costs, Net	51,000,000		31,000,000
Accretion of Discount	6,000,000
Purchase Price Premium, Unamortized	1,000,000
Acquisition Accounting Discount - Secured Debt	32,000,000
Line of Credit Facility, Maximum Borrowing Capacity	1,300,000,000
Debt Instrument, Face Amount	4,000,000,000		1,500,000,000
Line of Credit Facility, Amount Outstanding	4,800,000,000		9,378,000,000
Unsecured Debt	5,228,000,000		1,500,000,000
North America [Member]
Line of Credit Facility [Line Items]
Unsecured Debt	4,000,000,000		1,500,000,000
Senior Notes	4,000,000,000
International [Member]
Line of Credit Facility [Line Items]
Original Weighted-Average Interest Rate - Minimum	0.90%
Original Weighted-Average Interest Rate - Maximum	7.70%
Unsecured Debt	1,228,000,000
Secured Debt [Member] | North America [Member]
Line of Credit Facility [Line Items]
Original Weighted-Average Interest Rate - Minimum	0.98%	0.62%
Original Weighted-Average Interest Rate - Maximum	5.86%	12.84%
Securitization Notes Payable [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Face Amount	4,700,000,000
Debt, Weighted Average Interest Rate	1.60%
Debt Instrument Maturity Year	2021
Long-term Debt	1,900,000,000
Unsecured Debt [Member] | International [Member]
Line of Credit Facility [Line Items]
Original Weighted-Average Interest Rate - Minimum	0.50%
Original Weighted-Average Interest Rate - Maximum	9.00%
2013 Senior Notes [Member] | North America [Member]
Line of Credit Facility [Line Items]
Original Weighted-Average Interest Rate - Minimum	2.75%
Original Weighted-Average Interest Rate - Maximum	4.25%
Senior Notes	2,500,000,000
Senior Notes [Member] | North America [Member]
Line of Credit Facility [Line Items]
Original Weighted-Average Interest Rate - Minimum	2.75%
Original Weighted-Average Interest Rate - Maximum	6.75%
Senior Notes [Member] | North America [Member]
Line of Credit Facility [Line Items]
Unsecured Debt	$ 4,000,000,000
Credit Facility One [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate at Period End	0.70%
Credit Facility Two [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate at Period End	1.30%