Summary Of Significant Accounting Policies (Narrative) (Details) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended			4 Months Ended	6 Months Ended
	Apr. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Apr. 30, 2021 USD ($)	Jun. 30, 2021 USD ($) segment	Jun. 30, 2020 USD ($)	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
Successor [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Restricted cash		$ 50					$ 50
Accumulated deficit		(99)					$ (99)
Operating income		206
Net income		$ 99
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	$ 21			$ 50		$ 83		$ 107
Restricted cash									$ 58
Accumulated deficit									$ 8,975
Operating income	92			140		351		412
Net income	$ 4,481		$ 60	$ (181)	$ (186)	$ 4,541		$ (367)
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