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, 2022	Dec. 31, 2020
Consolidated Statements Of Income [Abstract]
Revenue	$ 2,231	$ 4,180	$ 5,787	$ 7,155
Operating expenses:
Cost of service	830	1,532	2,169	2,701
Selling, general and administrative expenses	537	1,131	1,745	1,648
Depreciation and amortization	506	734	1,182	1,598
Loss on disposal of Northwest Operations				162
Restructuring costs and other charges	7	21	99	87
Total operating expenses	1,880	3,418	5,195	6,196
Operating income	351	762	592	959
Investment and other income (loss), net (See Note 13)	1	(5)	554	(43)
Pension settlement costs			(55)	(159)
Loss on early extinguishment of debt				(72)
Reorganization items, net	4,171			(409)
Interest expense (See Note 10)	(118)	(257)	(492)	(762)
Income (loss) before income taxes	4,405	500	599	(486)
Income tax expense (benefit)	(136)	86	158	(84)
Net income (loss)	$ 4,541	$ 414	$ 441	$ (402)
Basic net earnings (loss) per share attributable to Frontier common shareholders	$ 43.42	$ 1.69	$ 1.80	$ (3.85)
Diluted net earnings (loss) per share attributable to Frontier common shareholders	$ 43.28	$ 1.68	$ 1.80	$ (3.85)
Total weighted average shares outstanding - basic	104,584	244,405	244,781	104,467
Total weighted average shares outstanding - diluted	104,924	245,885	245,280	104,467
Financial Designation, Predecessor and Successor [Fixed List]	Predecessor	Successor	Successor	Predecessor