Description Of Business And Summary Of Significant Accounting Policies (Narrative) (Details) item in Millions, $ in Millions	4 Months Ended	12 Months Ended
	Apr. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) employee segment item	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of subscribers | item		2.8
Number of employees | employee		15,600
Number of reportable segments | segment		1
Other Current Assets [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Restricted cash		$ 17
Other Assets [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Restricted cash		$ 34	$ 58
Customer Relationships - Business [Member] | Minimum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life		11 years
Customer Relationships - Business [Member] | Maximum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life		16 years
Trademarks and Tradenames [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Amortization method		5
Successor [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Customer surcharges	$ 83
Successor [Member] | Customer Relationships - Business [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life		11 years
Successor [Member] | Trademarks and Tradenames [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life		5 years
Predecessor [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Customer surcharges			$ 193	$ 221