Reorganization Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reorganization Items, net [Abstract]
Debtor Reorganization Items, Other Expense (Income)	$ 104		$ 104
Debtor Reorganization Items, Legal and Advisory Professional Fees	39		39
Debtor Reorganization Items, Debtor-in-Possession Facility Financing Costs	13		13	$ 0
Reorganization Items	$ 156	$ 0	$ 156	$ 0