Summary Of Significant Accounting Policies (Narrative) (Details) $ in Millions	3 Months Ended	4 Months Ended	9 Months Ended
	Sep. 30, 2020 USD ($)	Apr. 30, 2021 USD ($)	Sep. 30, 2021 USD ($) segment	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | segment			1
Customer Relationships - Wholesale [Member] | Maximum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life			16 years
Customer Relationships - Business [Member] | Minimum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life			11 years
Trademarks and Tradenames [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Amortization method			5 years
Successor [Member] | Other Current Assets [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Restricted cash			$ 17
Successor [Member] | Other Assets [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Restricted cash			$ 33
Successor [Member] | Customer Relationships - Wholesale [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life			16 years
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	$ 58	$ 83		$ 165
Predecessor [Member] | Other Assets [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Restricted cash					$ 58
Predecessor [Member] | Customer Base [Member] | Minimum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life			8 years
Predecessor [Member] | Customer Base [Member] | Maximum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life			12 years