Fresh Start Accounting Reorganization Adjustments - Liabilities Subject to Compromise (Details) - USD ($) $ in Millions	Jul. 01, 2019	Jun. 30, 2019
Reorganizations [Abstract]
Debt		$ 3,420
Interest payable		99
Accounts payable	$ (56)	(56)
Environmental reserve		43
Pension and other post employment benefit obligations	(33)	(33)
Financing fees	(19)
Dividends payable to parent		13
Other		8
Liabilities Subject to Compromise	3,672	$ 3,672
Repayment of 1st Lien Notes	(1,383)
Liabilities Subject to Compromise, Long-term liabilities	(32)
Reorganization Items, Liabilities Restated at Emergence	(140)
Total equity (deficit)	(1,156)
Proceeds from the Rights Offerings	300
Total fair value of equity issued in exchange for debt	(856)
Gain on settlement of LSTC	$ 1,293