Commitments And Contingencies (Narrative) (Details) $ in Millions		3 Months Ended		6 Months Ended	12 Months Ended
	Jan. 30, 2020 USD ($) item state	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2024 USD ($)
Commitments And Contingencies [Line Items]
Accounts payable and accrued liabilities		$ 1,196		$ 1,196		$ 1,033
Accounts payable		968		968		$ 758
Capital expenditure associated with vendor financing payments				$ 16
Accrued an incremental for legal disputes and settlements		$ 66
RDOF Program, Phase I [Member]
Commitments And Contingencies [Line Items]
Awarded amount	$ 371
Period to build gigabit capable broadband	10 years
Number of location to build gigabit capable broadband | item	127,000
Number of states to build gigabit capable broadband | state	8
RDOF Program, Phase II [Member]
Commitments And Contingencies [Line Items]
Annual support offered by the Federal Communications Commission					$ 313
Chief Executive Officer, Frontier’s Predecessor Company [Member]
Commitments And Contingencies [Line Items]
Settlement agreement amount			$ 25
Minimum [Member]
Commitments And Contingencies [Line Items]
Terms of lease arrangements		1 year		1 year
Maximum [Member]
Commitments And Contingencies [Line Items]
Terms of lease arrangements		99 years		99 years
Vendor financing liabilities included in other current liabilities		$ 0		$ 0