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Income Taxes - Narrative (Details) - USD ($) $ in Millions | 2 Months Ended | 4 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Dec. 31, 2021 | Oct. 19, 2021 | Dec. 31, 2023 | Dec. 31, 2022 | Jun. 30, 2021 | Jun. 30, 2020
Income Tax Examination [Line Items] |  |  |  |  |  |
Capitalized research and development |  |  | $ 10.1 | $ 5.6 |  |
Valuation allowance | $ 20.7 | $ 30.7 | 30.0 | 23.9 | $ 29.1 | $ 29.0
Increase (decrease) in valuation allowance |  | 1.6 | 6.1 | 3.2 | 0.1 |
Increases/(decreases) resulting from the Mirion Business Combination | 19.7 | 0.0 | 0.0 | (0.4) | 0.0 |
Tax credit carryforwards |  |  | 4.4 |  |  |
Unrecognized tax benefits | 6.6 | $ 6.5 | 8.4 | 6.9 | 5.0 | $ 0.8
Unrecognized tax benefits that would impact effective tax rate |  |  |  | 6.3 |  |
Deferred tax liabilities unrecognized tax benefits | 3.5 |  | 1.3 | 3.4 | 2.9 |
Interest and penalties | 0.9 |  | 1.2 | 0.9 | 0.6 |
Noncurrent Income Tax Payable |  |  |  |  |  |
Income Tax Examination [Line Items] |  |  |  |  |  |
Unrecognized tax benefits | $ 3.1 |  | 7.1 | $ 3.5 | $ 2.1 |
Minimum |  |  |  |  |  |
Income Tax Examination [Line Items] |  |  |  |  |  |
Unrecognized tax benefits |  |  | 0.0 |  |  |
Maximum |  |  |  |  |  |
Income Tax Examination [Line Items] |  |  |  |  |  |
Unrecognized tax benefits |  |  | 1.0 |  |  |
United States—State |  |  |  |  |  |
Income Tax Examination [Line Items] |  |  |  |  |  |
Operating loss carryforwards |  |  | 47.8 |  |  |
Foreign Jurisdiction |  |  |  |  |  |
Income Tax Examination [Line Items] |  |  |  |  |  |
Operating loss carryforwards |  |  | 60.6 |  |  |
US Controlled Foreign Corporations |  |  |  |  |  |
Income Tax Examination [Line Items] |  |  |  |  |  |
Amount of unrecognized deferred tax liability related to foreign subsidiaries |  |  | 21.2 |  |  |
Undistributed earnings of foreign subsidiaries |  |  | $ 182.9 |  |  |

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