Cash Flow Information - Non-cash Activities (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Supplemental Cash Flow Elements [Abstract]
Increase (decrease) in accrual for capital expenditures	$ 2.7	$ (3.5)
Operating leases, initial recognition	3.1	5.3
Operating leases, modifications and remeasurements	18.1	(10.7)
Finance leases, initial recognition	13.8	0.4
Finance leases, modifications and remeasurements	$ (1.5)	$ 8.3