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Fair Value Measurements - Narrative (Details) € in Millions, $ in Millions |  | 2 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jan. 05, 2024 USD ($) | Jan. 05, 2024 USD ($) | Jun. 30, 2024 USD ($) | Mar. 31, 2024 USD ($) | Jul. 02, 2023 USD ($) | Apr. 02, 2023 USD ($) | Jun. 30, 2024 USD ($) | Jul. 02, 2023 USD ($) | Dec. 31, 2023 USD ($) | May 31, 2024 USD ($) | Feb. 08, 2024 EUR (€) | Nov. 02, 2023 EUR (€) | Feb. 14, 2022 country | Jan. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unrealized gain (loss) on derivatives |  |  |  | $ (3.6) |  |  | $ 0.2 |  | $ (3.6) |  |  |  |  |
Foreign currency forward contract, asset, net |  |  | $ 0.2 |  |  |  | 0.2 |  |  |  |  |  |  |
Foreign currency forward contract, liability, net |  |  |  |  |  |  |  |  | 3.6 |  |  |  |  |
Payments for derivative instrument, investing activities | $ 2.4 |  |  |  |  |  | 2.4 | $ 0.0 |  |  |  |  |  |
Gain on forward contract |  |  | 0.0 | $ 1.2 | $ 0.0 |  | 1.2 | 0.0 |  |  |  |  |  |
Derivative Instruments Not Designated as Hedging Instruments, Loss |  | $ 2.4 |  |  |  |  |  |  |  |  |  |  |  |
Payment for contingent consideration liability, financing activities |  |  |  |  |  |  | 0.0 | 2.5 |  |  |  |  |  |
Foreign Exchange Forward |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative, notional amount | € |  |  |  |  |  |  |  |  |  |  | € 17.0 | € 90.0 |  |
Brazil |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Indemnification liabilities, expense (income) |  |  |  |  |  |  | (0.3) | 0.3 |  |  |  |  |  |
Brazil | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Indemnification liability |  |  | $ 8.8 |  |  |  | $ 8.8 |  |  |  |  |  |  |
Greenwood/Asher |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payment for contingent consideration liability, financing activities |  |  |  |  |  |  |  | $ 1.4 |  |  |  |  |  |
Motion Recruitment Partners, LLC |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Contingent consideration, maximum |  |  |  |  |  |  |  |  |  | $ 60.0 |  |  |  |
PersolKelly Pte. Ltd. |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity method investment, ownership percentage |  |  |  |  |  |  |  |  |  |  |  |  |  | 49.00%
Number of geographies in which entity operates | country |  |  |  |  |  |  |  |  |  |  |  |  | 10 |
Equity Ownership, Excluding Consolidated Entity and Equity Method Investee, Percentage |  |  | 2.50% |  |  |  | 2.50% |  |  |  |  |  |  |
Equity securities without readily determinable fair value, with changes in fair value in net income |  |  | $ 6.4 |  |  |  | $ 6.4 |  |  |  |  |  |  |
Other Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Money market funds |  |  | 7.7 |  |  |  | 7.7 |  | 8.0 |  |  |  |  |
Level 3 | Brazil |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Indemnification liability |  |  | 2.6 |  |  |  | 2.6 |  | 3.0 |  |  |  |  |
Level 3 | EMEA |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Indemnification liability |  |  | 2.0 |  |  |  | 2.0 |  |  |  |  |  |  |
Disposition, increase (decrease) in indemnification liabilities |  |  | (0.1) |  |  |  |  |  |  |  |  |  |  |
Level 3 | Greenwood/Asher |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payment for contingent consideration liability |  |  |  |  |  | $ 3.3 |  |  |  |  |  |  |  |
Level 3 | Motion Recruitment Partners, LLC |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business combination, contingent consideration, liability |  |  | 3.4 |  |  |  | 3.4 |  |  |  |  |  |  |
Contingent consideration, maximum |  |  | 60.0 |  |  |  | 60.0 |  |  |  |  |  |  |
Level 3 | Accounts Payable and Accrued Liabilities | Brazil |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Indemnification liability |  |  | 0.1 |  |  |  | 0.1 |  | 0.1 |  |  |  |  |
Level 3 | Other Long Term Liabilities | Brazil |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Indemnification liability |  |  | $ 2.5 |  |  |  | $ 2.5 |  | $ 2.9 |  |  |  |  |

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