Fair Value (Schedule of Fair Value Measurements, Liabilities, Using Significant Unobservable Inputs) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Liabilities	$ 115	$ 201
Recorded in Revenue, Liabilities	40	(104)
Recorded in Other Comprehensive Income, Liabilities	0	0
Purchases, Liabilities	0	0
Issuances, Liabilities	18	133
Sales, Liabilities	0	0
Settlements, Liabilities	(147)	(115)
Fair Value, ending balance, Liabilities	26	115
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of end of period	(1)	(27)
Accrued expenses and other liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Liabilities		20
Recorded in Revenue, Liabilities		0
Purchases, Liabilities
Issuances, Liabilities		0
Sales, Liabilities
Settlements, Liabilities		(20)
Fair Value, ending balance, Liabilities		0
Derivative instruments, liabilities | Accrued expenses and other liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Liabilities	115	181
Recorded in Revenue, Liabilities	40	(104)
Issuances, Liabilities	18	133
Settlements, Liabilities	(147)	(95)
Fair Value, ending balance, Liabilities	26	115
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of end of period	(1)	(27)
Foreign exchange contracts | Accrued expenses and other liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Liabilities	106	161
Recorded in Revenue, Liabilities	40	(93)
Issuances, Liabilities	18	133
Sales, Liabilities
Settlements, Liabilities	(147)	(95)
Fair Value, ending balance, Liabilities	17	106
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of end of period	(1)	(27)
Interest-rate contracts | Accrued expenses and other liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Liabilities		11
Recorded in Revenue, Liabilities		(11)
Purchases, Liabilities
Issuances, Liabilities		0
Sales, Liabilities
Settlements, Liabilities		0
Fair Value, ending balance, Liabilities		0
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of end of period		0
Other | Accrued expenses and other liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Liabilities	9	9
Recorded in Revenue, Liabilities	0	0
Purchases, Liabilities
Issuances, Liabilities	0	0
Sales, Liabilities
Settlements, Liabilities	0	0
Fair Value, ending balance, Liabilities	9	9
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of end of period	$ 0	$ 0