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
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, Current Liabilities	(19)
Liabilities Subject to Compromise, Long-term liabilities	(32)
Reorganization Items, Liabilities Restated at Emergence	(140)
Postconfirmation, Stockholders Equity, including portion attributable to non-controlling interest	(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