New Accounting Pronouncements Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash used in operating activities	$ 484	$ 444
Net cash used in financing activities	287	557
Prepaid Taxes	$ 110
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2016-09, Statutory Tax Withholding Component
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash used in operating activities		$ 5