Debt and Financing - Schedule of Carrying Values and Estimated Fair Values of Debt Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Book Value
Debt Instrument [Line Items]
Long-term debt, fair value	$ 874.7	$ 862.2
Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	865.3	864.7
Term Loan | New Term Loan Agreement | Book Value
Debt Instrument [Line Items]
Long-term debt, fair value	578.9	559.9
Term Loan | New Term Loan Agreement | Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	576.7	559.3
Lease financing obligations | Book Value
Debt Instrument [Line Items]
Long-term debt, fair value	226.0	231.3
Lease financing obligations | Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	222.9	233.7
Second A&R CDA | Book Value
Debt Instrument [Line Items]
Long-term debt, fair value	69.8	71.0
Second A&R CDA | Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	$ 65.7	$ 71.7