Restructuring Costs And Other Charges (Narrative) (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2020
Restructuring costs and other charges	$ 7	$ 21	$ 99	$ 87
Severance Costs	7	11	44
Transformation Initiatives [Member]
Restructuring costs and other charges				8
Lease Impairment Costs [Member]
Restructuring costs and other charges			44
Severance And Employee Costs [Member]
Restructuring costs and other charges	$ 7	11	44	7
Consulting And Advisory [Member]
Restructuring costs and other charges				$ 72
Other Restructuring [Member]
Restructuring costs and other charges			$ 11
Professional Fees [Member]
Restructuring costs and other charges		$ 10