XML 97 R78.htm IDEA: XBRL DOCUMENT v3.8.0.1
Equity-Based Compensation - Summary of Equity-based Compensation (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Equity-based compensation expense $ 43.7 $ 39.2 $ 31.2
Income tax benefit 15.3 13.3 10.9
Equity-based compensation expense (net of tax) 28.4 $ 25.9 $ 20.3
Compensation cost not yet recognized $ 32.0    
Compensation cost not yet recognized, period for recognition 1 year 7 months 6 days