Supplementary Information Foreign Currency Exchange Gain (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018		Jun. 30, 2017
Successor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax	$ 23		$ (109)
Foreign Currency Transaction Gain (Loss) Tax (Expense) Benefit	(49)		25
Foreign Currency Transaction Gain (Loss) After Tax	(26)		(84)
Predecessor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax		$ (140)			$ (199)
Foreign Currency Transaction Gain (Loss) Tax (Expense) Benefit		125			191
Foreign Currency Transaction Gain (Loss) After Tax		(15)			(8)
Subsidiary Monetary Position | Successor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax	(154)		(105)
Foreign Currency Transaction Gain (Loss) Tax (Expense) Benefit	(8)		24
Foreign Currency Transaction Gain (Loss) After Tax	(162)		(81)
Subsidiary Monetary Position | Predecessor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax		(54)			(28)
Foreign Currency Transaction Gain (Loss) Tax (Expense) Benefit		94			130
Foreign Currency Transaction Gain (Loss) After Tax		40			102
Hedging Program [Member] | Successor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax	177		(4)	[1]
Foreign Currency Transaction Gain (Loss) Tax (Expense) Benefit	(41)		1
Foreign Currency Transaction Gain (Loss) After Tax	$ 136		(3)
Hedging Program [Member] | Predecessor [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax		(86)			(171)
Foreign Currency Transaction Gain (Loss) Tax (Expense) Benefit		31			61
Foreign Currency Transaction Gain (Loss) After Tax		$ (55)			$ (110)
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)

[1] Includes a $(50) million foreign exchange loss for the six months ended June 30, 2018 related to adjustments to foreign currency exchange contracts as a result of U.S. tax reform.