Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Successor [Member]
Revenue		$ 4,180
Operating expenses:
Cost of service		1,532
Selling, general and administrative expenses		1,131
Depreciation and amortization		734
Goodwill impairment
Loss on disposal of Northwest Operations
Restructuring costs and other charges		21
Total operating expenses		3,418
Operating income (loss)		762
Investment and other income (loss), net		(5)
Pension settlement costs
Loss on early extinguishment of debt
Reorganization items, net
Interest expense (see Note 10)		(257)
Income (loss) before income taxes		500
Income tax (benefit) expense		86
Net income (loss) attributable to Frontier common shareholders		$ 414
Basic net income (loss) per share attributable to Frontier common shareholders		$ 1.69
Diluted net income (loss) per share attributable to Frontier common shareholders		$ 1.68
Total weighted average shares outstanding - basic		244,405
Total weighted average shares outstanding - diluted		245,885
Predecessor [Member]
Revenue	$ 2,231		$ 7,155	$ 8,107
Operating expenses:
Cost of service	830		2,701	3,057
Selling, general and administrative expenses	537		1,648	1,804
Depreciation and amortization	506		1,598	1,780
Goodwill impairment				5,725
Loss on disposal of Northwest Operations			162	446
Restructuring costs and other charges	7		87	168
Total operating expenses	1,880		6,196	12,980
Operating income (loss)	351		959	(4,873)
Investment and other income (loss), net	1		(43)	(37)
Pension settlement costs			(159)	(57)
Loss on early extinguishment of debt			(72)	(20)
Reorganization items, net	4,171		(409)
Interest expense (see Note 10)	(118)		(762)	(1,535)
Income (loss) before income taxes	4,405		(486)	(6,522)
Income tax (benefit) expense	(136)		(84)	(611)
Net income (loss) attributable to Frontier common shareholders	$ 4,541		$ (402)	$ (5,911)
Basic net income (loss) per share attributable to Frontier common shareholders	$ 43.42		$ (3.85)	$ (56.80)
Diluted net income (loss) per share attributable to Frontier common shareholders	$ 43.28		$ (3.85)	$ (56.80)
Total weighted average shares outstanding - basic	104,584		104,467	104,065
Total weighted average shares outstanding - diluted	104,924		104,467	104,065