Stockholders' Equity Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				$ 74,932
Ending Balance		$ 72,767		72,767
Predecessor [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income			$ 115		$ 237
Net other comprehensive income (loss)			358		846
Predecessor [Member] | Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance					(6,720)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax					(47)
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income					244
Net other comprehensive income (loss)					197
Ending Balance			(6,523)		(6,523)
Predecessor [Member] | Other Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance					(357)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax					0
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income					7
Net other comprehensive income (loss)					7
Ending Balance			(350)		(350)
Predecessor [Member] | Cumulative Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance					(2,843)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	[1]				653
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income					0
Net other comprehensive income (loss)					653
Ending Balance			(2,190)		(2,190)
Predecessor [Member] | Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance					7
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax					2
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income					(13)
Net other comprehensive income (loss)					(11)
Ending Balance			(4)		(4)
Predecessor [Member] | Unrealized gain (loss) on investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance					2
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax					1
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income			0		(1)
Net other comprehensive income (loss)					0
Ending Balance			2		2
Predecessor [Member] | Total
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance					(9,911)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax					609
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income					237
Net other comprehensive income (loss)					846
Ending Balance			$ (9,065)		$ (9,065)
Successor [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income		(6)		(7)
Net other comprehensive income (loss)		(1,936)		(964)
Successor [Member] | Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				128
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				9
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income				(2)
Net other comprehensive income (loss)				7
Ending Balance		135		135
Successor [Member] | Other Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				(53)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				0
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income				0
Net other comprehensive income (loss)				0
Ending Balance		(53)		(53)
Successor [Member] | Cumulative Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				(454)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	[1]			(966)
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income				0
Net other comprehensive income (loss)				(966)
Ending Balance		(1,420)		(1,420)
Successor [Member] | Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				(2)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				0
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income				(5)
Net other comprehensive income (loss)				(5)
Ending Balance		(7)		(7)
Successor [Member] | Unrealized gain (loss) on investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				0
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income		0		0
Net other comprehensive income (loss)				0
Ending Balance		0		0
Successor [Member] | Total
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				(381)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				(957)
Amounts Reclassified from Accumulated Other Comprehensive (Loss) Income				(7)
Net other comprehensive income (loss)				(964)
Ending Balance		$ (1,345)		$ (1,345)

[1] The cumulative translation adjustment gain for the six months ended June 30, 2017 is primarily driven by the weakening of the U.S. dollar ("USD") against the European Euro ("EUR"). The currency translation loss for the six months ended June 30, 2018 was primarily driven by the strengthening of the USD against the EUR and the Brazilian Real ("BRL").