Fair Value (Schedule of Fair Value Measurements, Liabilities, Using Significant Unobservable Inputs) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Liabilities	$ 17	$ 162	$ 26	$ 115
Recorded in Revenue, Liabilities	(5)	24	(14)	74
Recorded in Other Comprehensive Income, Liabilities	0	0	0	0
Purchases, Liabilities	0	0	0	0
Issuances, Liabilities	8	10	14	35
Sales, Liabilities	0	0	0	0
Settlements, Liabilities	(1)	(79)	(7)	(107)
Transfers in	0	0	0	0
Transfers out	0	0	0	0
Fair Value, ending balance, Liabilities	19	117	19	117
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of end of period	(3)	29	(5)	42
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	17	162	26	115
Recorded in Revenue, Liabilities	(5)	24	(14)	74
Recorded in Other Comprehensive Income, Liabilities	0	0	0	0
Purchases, Liabilities	0	0	0	0
Issuances, Liabilities	8	10	14	35
Sales, Liabilities	0	0	0	0
Settlements, Liabilities	(1)	(79)	(7)	(107)
Transfers in	0	0	0	0
Transfers out	0	0	0	0
Fair Value, ending balance, Liabilities	19	117	19	117
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of end of period	(3)	29	(5)	42
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	8	153	17	106
Recorded in Revenue, Liabilities	(5)	24	(14)	74
Recorded in Other Comprehensive Income, Liabilities	0	0	0	0
Purchases, Liabilities	0	0	0	0
Issuances, Liabilities	8	10	14	35
Sales, Liabilities	0	0	0	0
Settlements, Liabilities	(1)	(79)	(7)	(107)
Transfers in	0	0	0	0
Transfers out	0	0	0	0
Fair Value, ending balance, Liabilities	10	108	10	108
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of end of period	(3)	29	(5)	42
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	9	9
Recorded in Revenue, Liabilities	0	0	0	0
Recorded in Other Comprehensive Income, Liabilities	0	0	0	0
Purchases, Liabilities	0	0	0	0
Issuances, Liabilities	0	0	0	0
Sales, Liabilities	0	0	0	0
Settlements, Liabilities	0	0	0	0
Transfers in	0	0	0	0
Transfers out	0	0	0	0
Fair Value, ending balance, Liabilities	9	9	9	9
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of end of period	$ 0	$ 0	$ 0	$ 0