Restructuring 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, 2023	Dec. 31, 2022
Restructuring Cost and Reserve [Line Items]
Restructuring costs and other charges	$ 7	$ 21	$ 73	$ 99
Lease Impairment Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs and other charges			65	44
Severance And Employee Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs and other charges	$ 7	11		44
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs and other charges			$ 8	$ 11
Professional Fees [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs and other charges		$ 10