Fair Value Measurements (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	$ 41	$ 15
Total Liabilities at fair value	17	44
Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	17
Total Liabilities at fair value		11
Forward interest rate swap contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Liabilities at fair value	7	18
Money market investments related to the deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	17	15
Liabilities related to the deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Liabilities at fair value	17	15
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	18	15
Total Liabilities at fair value	17	17
Level 1 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	1
Total Liabilities at fair value		2
Fair value, assets, level 2 to level 1 transfers, amount	1	2
Level 1 | Forward interest rate swap contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Liabilities at fair value	0	0
Level 1 | Money market investments related to the deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	17	15
Level 1 | Liabilities related to the deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Liabilities at fair value	17	15
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	23	0
Total Liabilities at fair value	0	27
Level 2 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	16
Total Liabilities at fair value		9
Level 2 | Forward interest rate swap contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Liabilities at fair value	7	18
Level 2 | Money market investments related to the deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	0	0
Level 2 | Liabilities related to the deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Liabilities at fair value	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	0	0
Total Liabilities at fair value	0	0
Level 3 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	0
Total Liabilities at fair value		0
Level 3 | Forward interest rate swap contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Liabilities at fair value	0	0
Level 3 | Money market investments related to the deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets at fair value	0	0
Level 3 | Liabilities related to the deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Liabilities at fair value	$ 0	$ 0