Supplemental Balance Sheet Data and Cash Flow Information - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Interest paid	$ 5.4	$ 5.3	$ 10.9	$ 11.5
Taxes paid	4.3	0.9	5.0	1.5
Non-cash investing activities
Right-of-use assets obtained in exchange for lease liabilities	1.7	0.0	10.6	0.0
Equipment purchased under capital leases (ASC 840)	0.0	0.1	0.0	0.3
Capital expenditures in accounts payable	$ 0.1	$ 0.8	$ 0.4	$ 2.6