Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans (Details)

v3.8.0.1
Employee Benefit Plans (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Retirement Benefits [Abstract]      
Company contributions $ 35.9 $ 28.9 $ 30.3
Deferred Compensation Liability, Current and Noncurrent 61.5 53.8  
Deferred compensation plan amounts owed $ 59.5 $ 51.0