Leases - Future Minimum Lease Payments (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 monthly_payment	Dec. 31, 2017 USD ($)
Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2018		$ 20.7
2019		17.6
2020		15.6
2021		12.6
2022		10.6
Thereafter		25.5
Total minimum lease payments		102.6
Less: interest		(26.8)
Capital lease obligations		75.8
Less: current portion		(13.9)
Long-term capital lease obligations		61.9
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2018		80.3
2019		76.7
2020		75.0
2021		58.8
2022		50.6
Thereafter		173.9
Total minimum lease payments		$ 515.3
Forecast
Operating Leased Assets [Line Items]
Number of monthly obligation payments in fiscal year | monthly_payment	13