Commitments And Contingencies (Narrative) (Details) $ in Millions		3 Months Ended		12 Months Ended
	Jan. 30, 2020 USD ($) item state	Mar. 31, 2025 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2024 USD ($)
Commitments And Contingencies [Line Items]
Accounts payable and accrued liabilities		$ 1,119			$ 1,033
Accounts payable		895			$ 758
Vendor financing payments		$ 16
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
Maximum [Member]
Commitments And Contingencies [Line Items]
Terms of lease arrangements		99 years
Vendor financing liabilities included in other current liabilities		$ 1