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DISCONTINUED OPERATIONS - Cash Flow and Non-Cash Information Related to Discontinued Operations (Details) - USD ($) $ in Millions |  | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Sep. 12, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |
Proceeds from the sale of ATC TIPL |  |  |  | $ 0.0 | $ 2,158.8
Significant non-cash items: |  |  |  |  |
Loss on sale of ATC TIPL |  |  |  | 0.0 | 1,245.5
Discontinued Operations, Disposed of by Sale | ATC TIPL |  |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |
Proceeds from the sale of ATC TIPL |  |  |  | 0.0 | 2,158.8
Capital expenditures |  |  |  | 0.0 | (52.3)
Significant non-cash items: |  |  |  |  |
Depreciation, amortization and accretion |  |  |  | 0.0 | 96.0
Stock-based compensation expense |  |  | $ 6.8 | 0.0 | 10.9
Impairments, net loss on sale of long-lived assets, non-cash restructuring and merger related expenses |  |  |  | 0.0 | (2.3)
(Gain) loss on investments, unrealized foreign currency loss (gain) and other non-cash expense |  |  |  | 0.0 | (30.7)
Loss on sale of ATC TIPL |  | $ 0.0 | 1,245.5 | $ 0.0 | 1,245.5
Reclassification of cumulative translation adjustment | $ 1,100.0 |  | $ 1,100.0 |  | $ 1,072.3

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