Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenue	$ 821	$ 1,309	$ 2,036	$ 2,655
Operating Income (Loss)	(497)	(118)	(1,319)	(419)
Other Cost and Expense, Operating	(22)	(28)	(32)	(58)
Gain on Sale of Businesses, Net	0	(114)	0	(112)
Interest Expense, Net	59	160	117	315
Reorganization Items	0	0	9	0
Other Expense, Net	(11)	(1)	(36)	(10)
Loss Before Income Taxes	(567)	(279)	(1,481)	(744)
Total Assets	5,409		5,409		$ 7,293
Operating Segments
Segment Reporting Information [Line Items]
Revenue	821	1,309	2,036	2,655
Operating Income (Loss)	(8)	39	39	68
Other Cost and Expense, Operating	(463)	(239)	(1,306)	(535)
Operating Segments | Western Hemisphere
Segment Reporting Information [Line Items]
Revenue	310	719	898	1,445
Operating Income (Loss)	(23)	11	6	20
Total Assets	1,761		1,761		2,514
Operating Segments | Eastern Hemisphere
Segment Reporting Information [Line Items]
Revenue	511	590	1,138	1,210
Operating Income (Loss)	15	28	33	48
Total Assets	3,426		3,426		4,392
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Corporate	(26)	$ (32)	(52)	$ (64)
Total Assets	$ 222		$ 222		$ 387