XML 80 R64.htm IDEA: XBRL DOCUMENT v3.10.0.1
Retirement and Other Benefit Plans (Details)
$ in Millions
12 Months Ended
Dec. 31, 2018
USD ($)
plan
Dec. 31, 2017
USD ($)
Agreement
Dec. 31, 2016
USD ($)
Agreement
Retirement Benefits [Abstract]      
Number of defined contribution plans maintained by the company 4 4 4
Defined contribution retirement plan cost $ 31.2 $ 27.6 $ 23.7