Income Taxes Level 4 (Details) - Reconciliation of Differences Between Income Taxes For Continuing Operations and Provisions for Income Taxes - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes Reconciliation between Continuing Operations and Provisions for Income Taxes [Line Items]
Income tax (benefit) expense computed at federal statutory tax rate	$ (21)	$ 654	$ (26)	$ (77)
State tax (benefit) expense, net of federal benefit	(2)	10	1	0
Foreign tax rate (benefit) expense differential	(1)	2	9	(2)
Foreign source income (loss) subject to U.S. taxation	3	1	2	(45)
Non-deductible losses and other expenses	0	14	10	20
Increase (decrease) in the taxes due to changes in valuation allowance	20	(427)	25	(129)
Additional expense on foreign unrepatriated earnings	0	0	(1)	0
Additional expense for uncertain tax positions	1	46	18	5
Effective Income Tax Rate Reconciliation, Equity in Earnings (Losses) of Unconsolidated Subsidiary, Amount	(1)	0	0	(3)
Changes in enacted tax laws and tax rates	0	0	0	167
Transition tax expense	0	0	0	65
Effective income tax rate reconciliation, Fresh start and reorganization adjustment impact		(87)
write off net operating loss	(8)	9	0	17
Income tax (benefit) expense	$ (9)	$ 222	$ 40	$ 18