Cash Flow Information - Non-cash Activities (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Increase (decrease) in accrual for capital expenditures	$ 0.7		$ (4.1)
Operating leases, initial recognition	0.1	$ 4.3
Operating leases, modifications and remeasurements	11.9	0.7
Finance leases, initial recognition	10.0	0.0
Finance leases, modifications and remeasurements	$ (1.5)	$ 0.0