Long-Term Debt and Finance Leases - Summary (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Long-Term Debt and Capital Leases
Available borrowing capacity	$ 215.5
Long-term debt	2,289.1	$ 2,275.3
Finance lease liability	25.2	23.1
Total long-term debt and finance lease obligations	2,314.3	2,298.4
Debt issuance costs, net	(6.8)	(8.0)
Sub-total	2,307.5	2,290.4
Less current portion	(33.1)	(30.9)
Long-term portion	$ 2,274.4	2,259.5
Term B Loans
Long-Term Debt and Capital Leases
Effective interest rate (as a percent)	5.28%
Long-term debt	$ 2,210.1	2,220.3
Debt issuance costs, net	(5.2)	(6.0)
Net discount	7.2	8.4
Revolving Credit Facility
Long-Term Debt and Capital Leases
Available borrowing capacity	$ 215.5
Effective interest rate (as a percent)	3.19%
Long-term debt	$ 79.0	55.0
Debt issuance costs, net	(1.6)	$ (2.0)
Maximum borrowing capacity	300.0
Outstanding letters of credit	$ 5.5