Annual report pursuant to Section 13 and 15(d)

STOCK-BASED COMPENSATION - Total Stock-Based Compensation Expense (Details)

v3.20.4
STOCK-BASED COMPENSATION - Total Stock-Based Compensation Expense (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Stock-based compensation expense, before income taxes $ 54.7 $ 49.7 $ 42.5
Cost of services      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Stock-based compensation expense, before income taxes 11.2 10.7 9.5
Selling, general and administrative expenses      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Stock-based compensation expense, before income taxes $ 43.5 $ 39.0 $ 33.0