Restructuring and Asset Related Charges 2017 Restructuring Program (Details) - USD ($) $ in Millions	1 Months Ended		2 Months Ended		3 Months Ended														4 Months Ended	8 Months Ended	12 Months Ended
	Sep. 30, 2017	[1]	Aug. 31, 2017	[1]	Dec. 31, 2018		Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Dec. 31, 2017		Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2017	Aug. 31, 2017	Dec. 31, 2018	Dec. 31, 2016
2017 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve					$ 4								$ 19						$ 19		$ 4
Predecessor [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset Related Charges - Net			$ 11												$ 160		$ 152			$ 323		$ 556
Predecessor [Member] | 2017 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset Related Charges - Net																				313
Predecessor [Member] | Employee Severance [Member] | 2017 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset Related Charges - Net																				34
Predecessor [Member] | Asset Related Charges [Member] | 2017 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset Related Charges - Net																				$ 279
Successor [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Asset Related Charges - Net	$ 40				$ 115	[1]	$ 182		$ 91		$ 97		$ 140	[1]					$ 180		$ 485

[1] See Note 6 for additional information.