Description Of Business And Summary Of Significant Accounting Policies (Narrative) (Details)	3 Months Ended	4 Months Ended	8 Months Ended	12 Months Ended
	Mar. 31, 2022 USD ($)	Apr. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2023 USD ($) employee item state segment	Dec. 31, 2022 USD ($)	Dec. 31, 2020 USD ($)	Sep. 30, 2023 USD ($)
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of subscribers | item				2,900,000
Number of states of operation | state				25
Debtor-in-possession financing costs		$ 15,000,000				$ 121,000,000
Annual support accepted for commitment for RDOF				$ 37,000,000
Number of employees | employee				13,300
Number of reportable segments | segment				1
Reorganization Items		(4,171,000,000)				$ 409,000,000
Restricted cash				114,000,000	0
Short-term Investments				1,075,000,000	1,750,000,000
Customer surcharges		83,000,000
Lease Impairment	$ 44,000,000				44,000,000
Revenue recognition period, FCC's CAF Phase II subsidies				7 years
Provided funding period, for construction of broadband networks				10 years
Remaining outstanding principal				$ 11,231,000,000	$ 8,963,000,000
Number of stock plans | item				1
Securitization Trust Accounts [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Restricted cash, current				$ 42,000,000
Restricted cash, noncurrent				72,000,000
US Treasuries In Trust Account [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Restricted cash				63,000,000
Debt On Frontier Southwest Properties [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Remaining outstanding principal				$ 47,000,000			$ 47,000,000
Business And Wholesale [Member] | Minimum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life				11 years
Business And Wholesale [Member] | Maximum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life				16 years
Trademarks and Tradenames [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life				5 years