Fair Value Measurements (Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	$ (8)	$ (12)
Interest rate swaps	(2)	(3)
Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual funds	43	41
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	47	42
Total liabilities	(10)	(15)
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	43	41
Total liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	4	1
Total liabilities	(10)	(15)
Fair Value, Measurements, Recurring [Member] | Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual funds	43	41
Fair Value, Measurements, Recurring [Member] | Mutual Funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual funds	43	41
Fair Value, Measurements, Recurring [Member] | Mutual Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual funds	0	0
Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	(4)	(5)
Interest rate swaps	(2)	(3)
Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	0	0
Interest rate swaps	0	0
Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	(4)	(5)
Interest rate swaps	(2)	(3)
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps		(2)
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps		0
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps		(2)
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency forwards and swaps	4	1
Foreign currency forwards and swaps	(4)	(5)
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency forwards and swaps	0	0
Foreign currency forwards and swaps	0	0
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency forwards and swaps	4	1
Foreign currency forwards and swaps	$ (4)	$ (5)