Leases (Supplemental Cash Flow Information Related To Leases) (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Successor [Member]
Lessee, Lease, Description [Line Items]
Operating cash flows provided by operating leases		$ 63
Operating cash flows used by operating leases		(38)
Operating cash flows used by finance leases		(6)
Financing cash flows used by finance leases		(13)
Right-of-use assets obtained in exchange for lease liabilities, Operating leases		10
Right-of-use assets obtained in exchange for lease liabilities, Finance leases		$ 25
Predecessor [Member]
Lessee, Lease, Description [Line Items]
Operating cash flows provided by operating leases	$ 21		$ 67
Operating cash flows used by operating leases	(14)		(68)
Operating cash flows used by finance leases	(5)		(13)
Financing cash flows used by finance leases	(7)		(23)	$ (35)
Right-of-use assets obtained in exchange for lease liabilities, Operating leases	$ 8		28
Right-of-use assets obtained in exchange for lease liabilities, Finance leases			$ 3