Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022
Consolidated Statements Of Income [Abstract]
Revenue	$ 2,231	$ 4,180	$ 5,751	$ 5,787
Operating expenses:
Cost of service	830	1,532	2,125	2,169
Selling, general, and administrative expenses	537	1,131	1,646	1,745
Depreciation and amortization	506	734	1,415	1,182
Restructuring costs and other charges	7	21	73	99
Total operating expenses	1,880	3,418	5,259	5,195
Operating income	351	762	492	592
Investment and other income (loss), net (See Note 12)	1	(5)	278	554
Pension settlement costs				(55)
Reorganization items, net	4,171
Interest expense (See Note 9)	(118)	(257)	(653)	(492)
Income before income taxes	4,405	500	117	599
Income tax expense (benefit)	(136)	86	88	158
Net income	$ 4,541	$ 414	$ 29	$ 441
Basic net earnings per share attributable to Frontier common shareholders	$ 43.42	$ 1.69	$ 0.12	$ 1.80
Diluted net earnings per share attributable to Frontier common shareholders	$ 43.28	$ 1.68	$ 0.12	$ 1.80
Total weighted average shares outstanding - basic	104,584	244,405	245,517	244,781
Total weighted average shares outstanding - diluted	104,924	245,885	248,459	245,280
Financial Designation, Predecessor and Successor [Fixed List]	Predecessor	Successor	Successor	Successor