XML 36 R64.htm IDEA: XBRL DOCUMENT v3.20.1
Supplemental Financial Information (Other Current Assets) (Details) - USD ($)
$ in Millions
Mar. 31, 2020
Dec. 31, 2019
Supplemental Financial Information [Abstract]    
Materials and supplies $ 308.9 $ 340.1
Deferred costs 32.6 23.3
Prepaid taxes 45.5 36.2
Prepaid expenses 11.4 13.5
Other 29.1 33.4
Other current assets $ 427.5 $ 446.5