Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Gross number of share options (or share units) granted during the period.

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Stock Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	4 Months Ended	5 Months Ended	9 Months Ended
Stock Plans (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Apr. 30, 2021	Sep. 30, 2021	Sep. 30, 2021
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining unrecognized compensation cost associated with unvested restricted stock awards	$ 63		$ 63	$ 63
Weighted average period over which unvested restricted stock awards unrecognized compensation cost is expected to be recognized (in years)				2 years
Compensation expense		$ 1	4
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 4		$ 4
Successor [Member] \| Frontier Communications Parent, Inc. 2021 Management Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant under the plan (in shares)	15,600,000		15,600,000	15,600,000
Successor [Member] \| Restricted Stock Units And Performance Stock Units [Member] \| Frontier Communications Parent, Inc. 2021 Management Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate awarded shares				5,278,041