STOCKHOLDERS' DEFICIT - RSU, PSU activity (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024
Weighted Average Grant Date Fair Value
Taxes paid for restricted unit withholdings	$ 4.4	$ 2.2
RSU and PSU
Shares of RSU PSU and SPSU
Nonvested at the end of the period (in shares)	25,588
Weighted Average Grant Date Fair Value
Taxes paid for restricted unit withholdings	$ 4.4
RSU and PSU \| Class A common stock
Shares of RSU PSU and SPSU
Balance at the beginning of the period (in shares)	3,876,114
Granted (in shares)	5,422,243
Vested (in shares)	(1,161,440)
Forfeited (in shares)	(322,900)
Cancelled (in shares)	(1,052,237)
Nonvested at the end of the period (in shares)	6,761,780
Weighted Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share)	$ 7.92
Granted (in dollars per share)	3.57
Vested (in dollars per share)	8.33
Forfeited (in dollars per share)	5.83
Cancelled (in dollars per share)	8.62
Nonvested at the end of the period (in dollars per share)	$ 4.35
Tranche Years 2026 and 2027 awarded under the 2025 PSU award and Tranche Year 2026 awarded under the 2024 PSU award with grant date fair values to be determined in year 2026 and 2027, respectively	3,000,921
Total nonvested at March 31, 2025	9,762,701
RSU and PSU \| Special Award \| Class A common stock
Shares of RSU PSU and SPSU
Granted (in shares)	265,912
Vested (in shares)	(140,982)
Cancelled (in shares)	(124,930)
Weighted Average Grant Date Fair Value
Granted (in dollars per share)	$ 3.57
Vested (in dollars per share)	3.57
Cancelled (in dollars per share)	$ 3.57
Special Performance Stock \| Cumulative Adjusted EBITDA Target
Weighted Average Grant Date Fair Value
Percentage of performance target	100.00%
Special Performance Stock \| Cumulative Adjusted Free Cash Flow Target
Weighted Average Grant Date Fair Value
Percentage of performance target	100.00%
2025 Performance share award \| Meeting of strategic initiatives target
Weighted Average Grant Date Fair Value
Percentage of performance target	200.00%
2026 Performance share award \| Meeting of strategic initiatives target
Weighted Average Grant Date Fair Value
Percentage of performance target	100.00%

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of cancellation.

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Number of equity instruments other than options awarded for the next two fiscal years however the grant date fair values are subject to determination in that particular fiscal year under the share based compensation arrangement.

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Total number of equity instruments other than options outstanding including the awards for which the grant date fair values are subject to determination in that particular fiscal year under the share based compensation arrangement.

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Amount of cash outflow to satisfy grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
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-Publisher FASB
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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-Publisher FASB
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-Topic 718
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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The net total number of shares (or other type of equity) under an equity-based award plan, other than a stock option plan, that were granted, vested and forfeited during the reporting period.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
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-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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