Basis of Presentation and Summary of Significant Accounting Policies - Reclassifications (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cash and cash equivalents	$ 475	$ 429	$ 368	$ 358
Restatement adjustment prior years
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cash and cash equivalents	123
Accounts receivable	123
Net cash provided by operating activities	$ 123