Restricted Cash (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	$ 2,060	$ 1,958
Securitization Notes Payable [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	1,403	1,098
Revolving Credit Facility [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	293	477
Other Liabilities [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	364	383
North America Segment [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	1,106	978
North America Segment [Member] | Securitization Notes Payable [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	1,046	890
North America Segment [Member] | Revolving Credit Facility [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	26	62
North America Segment [Member] | Other Liabilities [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	34	26
International Segment [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	954	980
International Segment [Member] | Securitization Notes Payable [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	357	208
International Segment [Member] | Revolving Credit Facility [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	267	415
International Segment [Member] | Other Liabilities [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	$ 330	$ 357