Income Taxes Level 4 (Details) - USD ($)	6 Months Ended		12 Months Ended
	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2017	Jul. 01, 2019	Dec. 31, 2016
Valuation Allowance [Line Items]
Valuation allowance	$ (140,000,000)		$ (547,000,000)	$ (522,000,000)	$ (120,000,000)	$ (651,000,000)
Income tax benefit	9,000,000	$ (222,000,000)	(40,000,000)	(18,000,000)
Operating Loss Carryforwards, Valuation Allowance	58,000,000				$ 1,053,000,000
Disallowed interest expense carryforward	34,000,000		283,000,000
Global Intangible low tax income			21,000,000
Income tax expense related to reorganization adjustments		40,000,000
Gain (loss) recognized between fair value and tax basis		50,000,000
Tax Benefit for Removal of Valuation Allowance		10,000,000
Changes in enacted tax laws and tax rates	0	0	0	167,000,000
Transition tax expense	$ 0	$ 0	$ 0	65,000,000
net operating loss carryforward reduction				185,000,000
Valuation allowance, deferred tax asset, decrease amount				$ 234