Fair Value Measurements - Information about Assets and Liabilities Recorded at Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Assets:
Investments	$ 10	$ 9
Foreign Exchange Contracts	4	41
Total Assets at Fair Value	14	50
Liabilities:
Foreign Exchange Contracts	47	18
Total Liabilities at Fair Value	47	18
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)
Assets:
Investments	10	9
Foreign Exchange Contracts	0	0
Total Assets at Fair Value	10	9
Liabilities:
Foreign Exchange Contracts	0	0
Total Liabilities at Fair Value	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Investments	0	0
Foreign Exchange Contracts	4	41
Total Assets at Fair Value	4	41
Liabilities:
Foreign Exchange Contracts	47	18
Total Liabilities at Fair Value	47	18
Significant Unobservable Inputs (Level 3)
Assets:
Investments	0	0
Foreign Exchange Contracts	0	0
Total Assets at Fair Value	0	0
Liabilities:
Foreign Exchange Contracts	0	0
Total Liabilities at Fair Value	$ 0	$ 0