Leases Supplemental Lease Disclosures (Details) - USD ($) $ in Millions	1 Months Ended	11 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 13, 2019	Dec. 31, 2019
Leases [Abstract]
Operating Lease, Payments	$ 5	$ 131
Finance Lease, Interest Payment on Liability	0	4
Finance Lease, Principal Payments	1	8
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	2	59
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	0		$ 6
Sale and Leaseback Transaction, Gain (Loss), Net	$ 0	$ 34
Operating Lease, Weighted Average Remaining Lease Term	7 years 9 months 18 days		7 years 9 months 18 days
Finance Lease, Weighted Average Remaining Lease Term	6 years 8 months 12 days		6 years 8 months 12 days
Operating Lease, Weighted Average Discount Rate, Percent	9.20%		9.20%
Finance Lease, Weighted Average Discount Rate, Percent	9.10%		9.10%