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Stock-Based Compensation - Stock-Based Compensation Expense Recognized In Consolidated Statements of Operations (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |  |  |
Stock-based compensation expense | $ 98.6 | $ 62.6 | $ 69.0
Retirement Eligible Employees Equity Award |  |  |
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |  |  |
Stock-based compensation expense | 41.2 | 17.9 | 21.5
Cost of services and product development |  |  |
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |  |  |
Stock-based compensation expense | 35.0 | 29.7 | 29.1
Selling, general and administrative |  |  |
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |  |  |
Stock-based compensation expense | 63.6 | 32.9 | 39.4
Acquisition and integration charges |  |  |
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |  |  |
Stock-based compensation expense | $ 0.0 | $ 0.0 | $ 0.5

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