Pension Plans and Other Post Employment Benefit Plans Change in Projected Benefit Obligations, Plan Assets and Funded Status (Details) - USD ($) $ in Millions		3 Months Ended			4 Months Ended		8 Months Ended		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2017		Aug. 31, 2017		Dec. 31, 2018	Dec. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation at beginning of the period									$ 389
Benefit obligation at end of the period		$ 389			$ 389				349
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at beginning of period									20,284
Fair value of plan assets at end of period		20,284			20,284				18,918
Successor [Member] | Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation at beginning of the period	[1]				26,036				25,550
Service Cost					49				131
Interest Cost					247				752
Plan participants' contributions					6				10
Actuarial (gain) loss					(23)				(1,078)
Benefits Paid					(730)				(1,747)
Plan amendments					0				17
Net effects of acquisitions / divestitures / other					22				(12)
Effect of foreign exchange rates					(57)				(209)
Benefit obligation at end of the period		25,550	[1]		25,550	[1]	$ 26,036	[1]	23,414
Fair value of plan assets at beginning of period	[1]				20,395				20,284
Actual return on plan assets					549				(782)
Employer contributions					68				1,308
Plan participants' contributions					6				10
Benefits paid	[2]				(730)				(1,747)
Net effects of acquisitions / divestitures / other					29				(7)
Effect of foreign exchange rates					(33)				(148)
Fair value of plan assets at end of period		20,284	[1]		20,284	[1]	20,395	[1]	18,918
Funded (unfunded) status of plan		(5,266)			(5,266)				(4,496)
Successor [Member] | Pension Plan | Principal U.S. Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions									1,100
Lump-Sum Payments		140
Successor [Member] | Pension Plan | U.S. Plans with Plan Assets [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan		(3,628)			(3,628)				(2,890)
Successor [Member] | Pension Plan | Non-U.S. plans with plan assets [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan		(447)			(447)				(488)
Successor [Member] | Pension Plan | All other plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan	[3],[4]	(1,191)			(1,191)				(1,118)
Successor [Member] | Pension Plan | Plans of Discontinued Operations [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan		0			0				0
Successor [Member] | Other Post Employment Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation at beginning of the period					2,772				2,810
Service Cost					3				9
Interest Cost					26				85
Plan participants' contributions					12				38
Actuarial (gain) loss					68				(172)
Benefits Paid					(71)				(254)
Plan amendments					0				0
Net effects of acquisitions / divestitures / other					0				0
Effect of foreign exchange rates					0				(2)
Benefit obligation at end of the period		2,810			2,810		2,772		2,514
Fair value of plan assets at beginning of period					0				0
Actual return on plan assets					0				0
Employer contributions					59				216
Plan participants' contributions					12				38
Benefits paid					(71)				(254)
Net effects of acquisitions / divestitures / other					0				0
Effect of foreign exchange rates					0				0
Fair value of plan assets at end of period		0			0		0		0
Funded (unfunded) status of plan		(2,810)			(2,810)				(2,514)
Successor [Member] | Other Post Employment Benefits Plan | U.S. Plans with Plan Assets [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan		0			0				0
Successor [Member] | Other Post Employment Benefits Plan | Non-U.S. plans with plan assets [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan		0			0				0
Successor [Member] | Other Post Employment Benefits Plan | All other plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan		(2,810)			(2,810)				(2,514)
Successor [Member] | Other Post Employment Benefits Plan | Plans of Discontinued Operations [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan		$ 0			0				$ 0
Predecessor [Member] | Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation at beginning of the period					24,766		24,831
Service Cost							92			$ 174
Interest Cost							524			800
Plan participants' contributions							8
Actuarial (gain) loss							0
Benefits Paid							(1,118)
Plan amendments							0
Net effects of acquisitions / divestitures / other							0
Effect of foreign exchange rates							429
Benefit obligation at end of the period				$ 24,831			24,766			24,831
Fair value of plan assets at beginning of period					19,685		16,656
Actual return on plan assets							846
Employer contributions							3,024
Plan participants' contributions							8
Benefits paid							(1,118)
Net effects of acquisitions / divestitures / other							0
Effect of foreign exchange rates							269
Fair value of plan assets at end of period				16,656			19,685			16,656
Funded (unfunded) status of plan							(5,081)
Predecessor [Member] | Pension Plan | Principal U.S. Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions							2,900			230
Lump-Sum Payments				550
Predecessor [Member] | Pension Plan | U.S. Plans with Plan Assets [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan							(3,277)
Predecessor [Member] | Pension Plan | Non-U.S. plans with plan assets [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan							(609)
Predecessor [Member] | Pension Plan | All other plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan							(1,187)
Predecessor [Member] | Pension Plan | Plans of Discontinued Operations [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan							(8)
Predecessor [Member] | Other Post Employment Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation at beginning of the period					2,731		2,829
Service Cost							6			11
Interest Cost							60			87
Plan participants' contributions							26
Actuarial (gain) loss							0
Benefits Paid							(192)
Plan amendments							0
Net effects of acquisitions / divestitures / other							0
Effect of foreign exchange rates							2
Benefit obligation at end of the period				2,829			2,731			2,829
Fair value of plan assets at beginning of period					$ 0		0
Actual return on plan assets							0
Employer contributions							166
Plan participants' contributions							26
Benefits paid							(192)
Net effects of acquisitions / divestitures / other							0
Effect of foreign exchange rates							0
Fair value of plan assets at end of period				$ 0			0			$ 0
Funded (unfunded) status of plan							(2,731)
Predecessor [Member] | Other Post Employment Benefits Plan | U.S. Plans with Plan Assets [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan							0
Predecessor [Member] | Other Post Employment Benefits Plan | Non-U.S. plans with plan assets [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan							0
Predecessor [Member] | Other Post Employment Benefits Plan | All other plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan							(2,731)
Predecessor [Member] | Other Post Employment Benefits Plan | Plans of Discontinued Operations [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded (unfunded) status of plan							$ 0

[1] The benefit obligation and the fair value of plan assets at the beginning of the period September 1 through December 31, 2017, reflects the remeasurement of the plans at the Merger Effectiveness Time.

[2] In the fourth quarter of 2017, about $140 million of lump-sum payments were made from the principal U.S. pension plan trust fund to a group of separated, vested plan participants who were extended a limited-time opportunity and voluntarily elected to receive their pension benefits in a single lump-sum payment.

[3] As of December 31, 2018, and December 31, 2017, $349 million and $389 million respectively of the benefit obligations are supported by funding under the Trust agreement, defined in the "Trust Assets" section below.

[4] Includes pension plans maintained around the world where funding is not customary.