Other Intangibles (Components Of Other Intangibles) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Successor [Member]
Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,441
Accumulated Amortization	(134)
Net Carrying Amount	4,307
Successor [Member] | Customer Relationships - Business [Member]
Intangible Assets [Line Items]
Gross Carrying Amount	800
Accumulated Amortization	(30)
Net Carrying Amount	770
Successor [Member] | Customer Relationships - Wholesale [Member]
Intangible Assets [Line Items]
Gross Carrying Amount	3,491
Accumulated Amortization	(91)
Net Carrying Amount	3,400
Successor [Member] | Trademarks and Tradenames [Member]
Intangible Assets [Line Items]
Gross Carrying Amount	150
Accumulated Amortization	(13)
Net Carrying Amount	$ 137
Predecessor [Member]
Intangible Assets [Line Items]
Gross Carrying Amount		$ 4,526
Accumulated Amortization		(3,849)
Net Carrying Amount		677
Predecessor [Member] | Customer Base [Member]
Intangible Assets [Line Items]
Gross Carrying Amount		4,332
Accumulated Amortization		(3,781)
Net Carrying Amount		551
Predecessor [Member] | Trade Name [Member]
Intangible Assets [Line Items]
Gross Carrying Amount		122
Net Carrying Amount		122
Predecessor [Member] | Royalty Agreement [Member]
Intangible Assets [Line Items]
Gross Carrying Amount		72
Accumulated Amortization		(68)
Net Carrying Amount		$ 4