Debt and Financing - Schedule of Carrying Values and Estimated Fair Values of Debt Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Book Value
Debt Instrument [Line Items]
Long-term debt, fair value	$ 862.2	$ 874.9
Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	864.7	850.7
Prior Term Loan | Book Value
Debt Instrument [Line Items]
Long-term debt, fair value		559.4
Prior Term Loan | Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value		546.0
New Term Loan | Book Value
Debt Instrument [Line Items]
Long-term debt, fair value	559.9
New Term Loan | Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	559.3
Lease financing obligations | Book Value
Debt Instrument [Line Items]
Long-term debt, fair value	231.3	242.2
Lease financing obligations | Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	233.7	234.7
Second A&R CDA | Book Value
Debt Instrument [Line Items]
Long-term debt, fair value	71.0	73.3
Second A&R CDA | Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	$ 71.7	$ 70.0