Long-Term Debt (Schedule Of Secured And Unsecured Debt) (Details) - USD ($)		12 Months Ended
	Aug. 08, 2023	Dec. 31, 2023	Dec. 31, 2022	May 12, 2022	Dec. 31, 2020
Debt Instrument [Line Items]
Principal outstanding		$ 11,231,000,000	$ 8,963,000,000
Weighted average interest rate		7.103%	6.76%
Debt prior to reclassification to liabilities subject to compromise					$ 10,949,000,000
First Lien Notes Due 5/15/2030 [Member]
Debt Instrument [Line Items]
Interest rate				8.75%
First Lien Notes Due 3/15/2031 [Member]
Debt Instrument [Line Items]
Interest rate				8.625%
Series 2023-1 Revenue Term Notes Class A-2 Due 7/20/2028 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 1,119,000,000
Interest rate	6.60%	6.60%
Proceeds from issuance of secured debt	$ 1,100,000,000
Final Maturity Date		Aug. 20, 2053
Series 2023-1 Revenue Term Notes Class B Due 7/20/2028 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 155,000,000
Interest rate	8.30%	8.30%
Proceeds from issuance of secured debt	$ 155,000,000
Final Maturity Date		Aug. 20, 2053
Series 2023-1 Revenue Term Notes Class C Due 7/20/2028 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 312,000,000
Interest rate	11.50%	11.50%
Proceeds from issuance of secured debt	$ 312,000,000
Final Maturity Date		Aug. 20, 2053
Fiber Term Notes [Member]
Debt Instrument [Line Items]
Proceeds from issuance of secured debt	$ 1,600,000,000
Secured Debt [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 8,848,000,000	$ 8,113,000,000
Secured Debt [Member] | Term Loan Due 10/8/2027 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 1,435,000,000	$ 1,450,000,000
Interest rate		9.22%	8.50%
Final Maturity Date		Oct. 08, 2027
Secured Debt [Member] | First Lien Notes Due 10/15/2027 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 1,150,000,000	$ 1,150,000,000
Interest rate		5.875%	5.875%
Final Maturity Date		Oct. 15, 2027
Secured Debt [Member] | First Lien Notes Due 5/1/2028 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 1,550,000,000	$ 1,550,000,000
Interest rate		5.00%	5.00%
Final Maturity Date		May 01, 2028
Secured Debt [Member] | First Lien Notes Due 5/15/2030 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 1,200,000,000	$ 1,200,000,000
Interest rate		8.75%	8.75%
Final Maturity Date		May 15, 2030
Secured Debt [Member] | First Lien Notes Due 3/15/2031 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 750,000,000
Interest rate		8.625%
Final Maturity Date		Mar. 15, 2031
Secured Debt [Member] | Second Lien Notes Due 5/1/2029 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 1,000,000,000	$ 1,000,000,000
Interest rate		6.75%	6.75%
Final Maturity Date		May 01, 2029
Secured Debt [Member] | Second Lien Notes Due 11/1/2029 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 750,000,000	$ 750,000,000
Interest rate		5.875%	5.875%
Final Maturity Date		Nov. 01, 2029
Secured Debt [Member] | Second Lien Notes Due 1/15/2030 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 1,000,000,000	$ 1,000,000,000
Interest rate		6.00%	6.00%
Final Maturity Date		Jan. 15, 2030
Secured Debt [Member] | IDRB Due 5/1/2030 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 13,000,000	$ 13,000,000
Interest rate		6.20%	6.20%
Final Maturity Date		May 01, 2030
Secured Subsidiary Debt [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 1,633,000,000	$ 100,000,000
Secured Subsidiary Debt [Member] | Debentures Due 11/15/2031 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 47,000,000	$ 100,000,000
Interest rate		8.50%	8.50%
Final Maturity Date		Nov. 15, 2031
Secured Subsidiary Debt [Member] | Series 2023-1 Revenue Term Notes Class A-2 Due 7/20/2028 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 1,119,000,000
Interest rate		6.60%
Final Maturity Date		Jul. 20, 2028
Secured Subsidiary Debt [Member] | Series 2023-1 Revenue Term Notes Class B Due 7/20/2028 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 155,000,000
Interest rate		8.30%
Final Maturity Date		Jul. 20, 2028
Secured Subsidiary Debt [Member] | Series 2023-1 Revenue Term Notes Class C Due 7/20/2028 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 312,000,000
Interest rate		11.50%
Final Maturity Date		Jul. 20, 2028
Unsecured Subsidiary Debt [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 750,000,000	$ 750,000,000
Unsecured Subsidiary Debt [Member] | Debentures Due 5/15/2027 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 200,000,000	$ 200,000,000
Interest rate		6.75%	6.75%
Final Maturity Date		May 15, 2027
Unsecured Subsidiary Debt [Member] | Debentures Due 2/1/2028 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 300,000,000	$ 300,000,000
Interest rate		6.86%	6.86%
Final Maturity Date		Feb. 01, 2028
Unsecured Subsidiary Debt [Member] | Debentures Due 2/15/2028 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 200,000,000	$ 200,000,000
Interest rate		6.73%	6.73%
Final Maturity Date		Feb. 15, 2028
Unsecured Subsidiary Debt [Member] | Debentures Due 10/15/2029 [Member]
Debt Instrument [Line Items]
Principal outstanding		$ 50,000,000	$ 50,000,000
Interest rate		8.40%	8.40%
Final Maturity Date		Oct. 15, 2029