Fair Value Of Financial Instruments (Pension Plan Assets Measured At Fair Value On Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Plan Assets, at Fair Value			$ 32
Successor [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	$ 2,174
Common/Collective Trusts	510
Interest and Dividend Receivable	5
Due from Broker for Securities Sold	28
Receivable Associated with Insurance Contract	6
Due to Broker for Securities Purchased	(68)
Total Plan Assets, at Fair Value	2,655
Successor [Member] | Cash and Cash Equivalents [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	39
Successor [Member] | U.S. Government Obligations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	62
Successor [Member] | Corporate and Other Obligations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	525
Successor [Member] | Common Stock [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	496
Successor [Member] | Interest in Registered Investment Companies [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	887
Successor [Member] | Interest in Limited Partnerships and Limited Liability Corporations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	165
Successor [Member] | Fair Value, Inputs, Level 1 [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	1,422
Successor [Member] | Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	39
Successor [Member] | Fair Value, Inputs, Level 1 [Member] | Common Stock [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	496
Successor [Member] | Fair Value, Inputs, Level 1 [Member] | Interest in Registered Investment Companies [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	887
Successor [Member] | Fair Value, Inputs, Level 2 [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	587
Successor [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government Obligations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	62
Successor [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate and Other Obligations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	525
Successor [Member] | Fair Value, Inputs, Level 3 [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	165
Successor [Member] | Fair Value, Inputs, Level 3 [Member] | Interest in Limited Partnerships and Limited Liability Corporations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	$ 165
Predecessor [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		$ 1,428
Common/Collective Trusts		1,073
Interest in Registered Investment Companies		32
Interest and Dividend Receivable		5
Due from Broker for Securities Sold		22
Receivable Associated with Insurance Contract		7
Due to Broker for Securities Purchased		(60)
Total Plan Assets, at Fair Value		2,507
Predecessor [Member] | Cash and Cash Equivalents [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		55
Predecessor [Member] | U.S. Government Obligations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		48
Predecessor [Member] | Corporate and Other Obligations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		506
Predecessor [Member] | Common Stock [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		510
Predecessor [Member] | Preferred Stock [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		3
Predecessor [Member] | Interest in Registered Investment Companies [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		140
Predecessor [Member] | Interest in Limited Partnerships and Limited Liability Corporations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		166
Predecessor [Member] | Fair Value, Inputs, Level 1 [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		708
Predecessor [Member] | Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		55
Predecessor [Member] | Fair Value, Inputs, Level 1 [Member] | Common Stock [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		510
Predecessor [Member] | Fair Value, Inputs, Level 1 [Member] | Preferred Stock [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		3
Predecessor [Member] | Fair Value, Inputs, Level 1 [Member] | Interest in Registered Investment Companies [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		140
Predecessor [Member] | Fair Value, Inputs, Level 2 [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		554
Predecessor [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government Obligations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		48
Predecessor [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate and Other Obligations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		506
Predecessor [Member] | Fair Value, Inputs, Level 3 [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		166
Predecessor [Member] | Fair Value, Inputs, Level 3 [Member] | Interest in Limited Partnerships and Limited Liability Corporations [Member] | Pension [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value		$ 166