Supplementary Information Foreign Currency Exchange Gain (Loss) (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2017	Aug. 31, 2017	Dec. 31, 2018		Dec. 31, 2016
Successor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax	$ 8		$ (110)
Foreign Currency Transaction Gain (Loss) Tax	(36)		(2)
Foreign Currency Transaction Gain (Loss) After Tax	(28)		(112)
Predecessor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax		$ (394)			$ (106)
Foreign Currency Transaction Gain (Loss) Tax		372			(16)
Foreign Currency Transaction Gain (Loss) After Tax		(22)			(122)
Subsidiary Monetary Position | Successor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax	(83)		(204)	[1]
Foreign Currency Transaction Gain (Loss) Tax	(3)		19
Foreign Currency Transaction Gain (Loss) After Tax	(86)		(185)
Subsidiary Monetary Position | Predecessor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax		37			198
Foreign Currency Transaction Gain (Loss) Tax		217			(126)
Foreign Currency Transaction Gain (Loss) After Tax		254			72
Hedging Program [Member] | Successor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax	91		94	[2]
Foreign Currency Transaction Gain (Loss) Tax	(33)		(21)
Foreign Currency Transaction Gain (Loss) After Tax	$ 58		73
Hedging Program [Member] | Predecessor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax		(431)			(304)
Foreign Currency Transaction Gain (Loss) Tax		155			110
Foreign Currency Transaction Gain (Loss) After Tax		$ (276)			$ (194)
Tax Reform Foreign Currency Exchange Impact [Member] | Hedging Program [Member] | Successor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax			50
Argentina, Pesos | Hedging Program [Member] | Successor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax			$ 75

[1] Includes a net $75 million pre-tax exchange loss associated with the devaluation of the Argentine peso for the twelve months ended December 31, 2018.

[2] Includes a $50 million foreign exchange loss for the twelve months ended December 31, 2018 related to adjustments to foreign currency exchange contracts as a result of U.S. tax reform.