Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Consolidated Statements Of Operations [Abstract]
Revenue	$ 1,511	$ 1,462
Operating expenses:
Cost of service	521	522
Selling, general, and administrative expenses	433	428
Depreciation and amortization	445	388
Restructuring costs and other charges	36	34
Total operating expenses	1,435	1,372
Operating income	76	90
Investment and other income, net (See Note 11)	49	112
Interest expense	(200)	(199)
Income (loss) before income taxes	(75)	3
Income tax expense (benefit)	(11)	2
Net income (loss)	$ (64)	$ 1
Basic net earnings (loss) per share attributable to Frontier common shareholders	$ (0.26)	$ 0.00
Diluted net earnings (loss) per share attributable to Frontier common shareholders	$ (0.26)	$ 0.00
Total weighted average shares outstanding - basic	249,830	246,301
Total weighted average shares outstanding - diluted	249,830	247,040