Restructuring (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2016
OTG [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Accelerated Depreciation	$ 21
Norco [Member]
Restructuring Cost and Reserve [Line Items]
Norco Restructuring and Related Cost, Accelerated Depreciation			$ 76
Loss on Contract Termination		$ 25	23
Restructuring Reserve, Accrual Adjustment	2
Other Liabilities	19		19
Norco related Other liabilities, Noncurrent	2		2
Costs Incurred, Asset Retirement Obligation Incurred		$ 30
Costs Incurred, Asset Retirement Obligation Incurred			30
Asset Retirement Obligation, Revision of Estimate	11
Norco ARO Liability	14		14
Norco ARO related Other liabilities, Noncurrent	2		2
Restructuring and Related Cost, Incurred Cost	$ 3		$ 13