Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Revenue	$ 903	$ 821	$ 1,735	$ 2,036
Operating Income (Loss)	25	(497)	12	(1,319)
Operating income (loss) before impairment and other charges	17	(34)	4	(13)
Restructuring Charges	0	(57)	0	(83)
Interest Expense	(72)	(59)	(142)	(117)
Reorganization Items	0	0	0	(9)
Other Expense, Net	(11)	(11)	(15)	(36)
Loss Before Income Taxes	(58)	(567)	(145)	(1,481)
Assets	5,160		5,160		$ 5,434
Elimination of Intercompany margins associated with transfers of assets and inventory	1	10	1	18
Impairments and Other Charges (Credits), Net	8	(406)	8	(1,223)
Operating Segments
Segment Reporting Information [Line Items]
Revenue	903	821	1,735	2,036
Operating Income (Loss)	34	(8)	39	39
Impairments and Other Charges (Credits), Net			8	(1,223)
Operating Segments | Western Hemisphere
Segment Reporting Information [Line Items]
Revenue	425	310	815	898
Operating Income (Loss)	28	(23)	52	6
Operating Segments | Eastern Hemisphere
Segment Reporting Information [Line Items]
Revenue	478	511	920	1,138
Operating Income (Loss)	6	15	(13)	33
Corporate, Non-Segment
Segment Reporting Information [Line Items]
General and Administrative Expense	$ (17)	$ (26)	$ (35)	$ (52)