Long-Term Debt (Narrative) (Details)						1 Months Ended	4 Months Ended	12 Months Ended
	Aug. 08, 2023 USD ($)	Oct. 13, 2021 USD ($)	Apr. 30, 2021 USD ($) shares	Nov. 25, 2020 USD ($)	Oct. 08, 2020 USD ($)	Sep. 30, 2023 USD ($)	Apr. 30, 2021 USD ($) shares	Dec. 31, 2023 USD ($) item	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2022 USD ($)	May 12, 2022 USD ($)
Debt Instrument [Line Items]
Principal outstanding								$ 11,231,000,000			$ 8,963,000,000
Weighted average interest rate								7.103%			6.76%
Remaining outstanding principal								$ 11,231,000,000			$ 8,963,000,000
Financing obligation for contributions of real property to pension plan									$ 37,000,000	$ 37,000,000
Lease term of contributed property										20 years
Combined average aggregate annual rent										$ 5,000,000
Gain (loss) on contribution of property to defined benefit								0
Interest expense							$ 450,000,000
Finance lease liability obligation								$ 53,000,000
Securitized Financing Facility [Member]
Debt Instrument [Line Items]
Interest rate								5.00%
Line of credit facility maximum borrowing capacity								$ 500,000,000
Number of available extensions of repayment date | item								2
Debt instrument, extension terms								1 year
First Lien Notes Due 3/15/2031 [Member]
Debt Instrument [Line Items]
Aggregate principal amount												$ 750,000,000
Interest rate												8.625%
First Lien Notes Due 4/1/2027 [Member]
Debt Instrument [Line Items]
Interest rate								8.00%
Final Maturity Date								Apr. 01, 2027
First Lien Notes Due 5/15/2030 [Member]
Debt Instrument [Line Items]
Aggregate principal amount												$ 1,200,000,000
Interest rate												8.75%
Second Lien Notes Due 4/1/2026 [Member]
Debt Instrument [Line Items]
Interest rate								8.50%
Final Maturity Date								Apr. 01, 2026
Term Loan Facility [Member] | SOFR [Member]
Debt Instrument [Line Items]
Interest rate margin								3.75%
Term Loan Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest rate margin								2.75%
Term Loan Facility [Member] | SOFR Floor [Member]
Debt Instrument [Line Items]
Interest rate margin								0.75%
Revolving Facility [Member]
Debt Instrument [Line Items]
Letters of credit outstanding								$ 358,000,000
Available borrowing capacity								$ 542,000,000
Line of Credit Facility, Maximum Permitted Leverage Ratio - Initial Covenant Term								3.50%
Line of Credit Facility, Maximum Permitted Leverage Ratio - 2nd Covenant Term								3.25%
Line of Credit Facility, Maximum Permitted Leverage Ratio - 3rd Covenant Term								3.00%
Line of credit facility maximum borrowing capacity								$ 900,000,000
Revolving Facility [Member] | SOFR [Member]
Debt Instrument [Line Items]
Interest rate margin								3.50%
Revolving Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest rate margin								2.50%
Revolving Facility [Member] | SOFR Floor [Member]
Debt Instrument [Line Items]
Interest rate margin								0.00%
Revolving Facility - After April 30, 2025 [Member]
Debt Instrument [Line Items]
Days prior to maturity to meet threshold to not accelerate debt								91 days
Line of credit facility maximum borrowing capacity								$ 850,000,000
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
Remaining outstanding principal								$ 1,119,000,000
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
Remaining outstanding principal								$ 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
Remaining outstanding principal								$ 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
Debt, original issue discounts	$ 58,000,000
Debt On Frontier Southwest Properties [Member]
Debt Instrument [Line Items]
Principal outstanding						$ 47,000,000		$ 47,000,000
Remaining outstanding principal						47,000,000		47,000,000
Senior Secured Notes [Member] | Second Lien Notes Due 2030 [Member]
Debt Instrument [Line Items]
Aggregate principal amount		$ 1,000,000,000.0
Interest rate		6.00%
Maturity year		2030
Senior Secured Notes [Member] | DIP-to-Exit First Lien Notes Due 10/15/2027 [Member]
Debt Instrument [Line Items]
Aggregate principal amount					$ 1,150,000,000
Interest rate					5.875%
Final Maturity Date					Oct. 15, 2027
Senior Secured Notes [Member] | DIP-to-Exit First Lien Notes Due 5/1/2028 [Member]
Debt Instrument [Line Items]
Aggregate principal amount				$ 1,550,000,000
Interest rate				5.00%
Final Maturity Date				May 01, 2028
Senior Secured Notes [Member] | Second Lien Notes Due 05/01/2029 [Member]
Debt Instrument [Line Items]
Aggregate principal amount				$ 1,000,000,000.0
Interest rate				6.75%
Final Maturity Date				May 01, 2029
Senior Secured Notes [Member] | Takeback Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount			$ 750,000,000				$ 750,000,000
Interest rate			5.875%				5.875%
Final Maturity Date			Nov. 01, 2029
Senior Notes [Member]
Debt Instrument [Line Items]
Extinguishment of debt, amount						$ 53,000,000
Common stock shares issued | shares			244,401,000				244,401,000
Secured Debt [Member]
Debt Instrument [Line Items]
Principal outstanding								8,848,000,000			8,113,000,000
Remaining outstanding principal								8,848,000,000			8,113,000,000
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%
Remaining outstanding principal								$ 1,150,000,000			$ 1,150,000,000
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%
Remaining outstanding principal								$ 1,550,000,000			$ 1,550,000,000
Final Maturity Date								May 01, 2028
Secured Debt [Member] | First Lien Notes Due 3/15/2031 [Member]
Debt Instrument [Line Items]
Principal outstanding								$ 750,000,000
Interest rate								8.625%
Remaining outstanding principal								$ 750,000,000
Final Maturity Date								Mar. 15, 2031
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%
Remaining outstanding principal								$ 1,200,000,000			$ 1,200,000,000
Final Maturity Date								May 15, 2030