Financial Instruments and Fair Value - Narrative (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Aggregate cost basis for non-qualified deferred compensation plan	$ 42,800,000	$ 42,800,000	$ 37,200,000
Acquisition earnout accruals, non-current	39,700,000	39,700,000	38,601,000
Impairment		16,224,000
Equity investment without readily determinable fair value, amount	11,000,000	11,000,000	0
On-Demand Talent Reporting Unit
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impairment	14,800,000	14,800,000
Europe Reporting Unit
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impairment	1,500,000	1,500,000
Earnout \| Fair Value, Inputs, Level 3 \| Non-Current and Other Non-Current Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Acquisition earnout accruals, non-current	39,700,000	39,700,000	38,600,000
Contingent Compensation \| Fair Value, Inputs, Level 3 \| Current Accrued Salaries and Benefits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Acquisition earnout accruals, current	4,000,000	4,000,000	6,000,000
Contingent Compensation \| Fair Value, Inputs, Level 3 \| Non-Current Accrued Salaries and Benefits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Acquisition earnout accruals, non-current	$ 14,400,000	$ 14,400,000	$ 12,900,000

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