Revision of Previously Issued Financial Statements (Details) - USD ($) $ in Millions	3 Months Ended		15 Months Ended	48 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization	$ 1,931	$ 1,770
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization	6
Lump Sum Payments Immediately Recognized, Should Have Been Deferred And Amortized | Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Deferred charges	$ 29		$ 29	$ 29	$ 23
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization			7	$ 34
AccrualsForSubstrateLiabilitiesAndAssociatedCostOfSales [Member] | Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization			$ 7