Debt and Financing - Schedule of Outstanding Debt (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Par Value	$ 902.8	$ 890.0
Discount	(28.1)	(7.8)
Debt Issuance Costs	(12.5)	(7.3)
Book Value	862.2	874.9
Book Value, Current Maturities	(4.1)	(20.7)
Par Value, Excluding Current Maturities	898.7	869.3
Premium (Discount), Excluding Current Maturities	(28.1)	(7.8)
Debt Issuance Costs, Noncurrent	(12.5)	(7.3)
Book Value, Excluding Current Maturities	858.1	854.2
New Term Loan
Debt Instrument [Line Items]
Par Value	600.0
Discount	(28.1)
Debt Issuance Costs	(12.0)
Book Value	$ 559.9
Effective Interest Rate	10.50%
ABL Facility | 2014 ABL Facility Credit Agreement
Debt Instrument [Line Items]
Par Value	$ 0.0	0.0
Discount	0.0	0.0
Debt Issuance Costs	0.0	0.0
Book Value	0.0	0.0
Secured Second A&R CDA
Debt Instrument [Line Items]
Par Value	26.0	26.9
Discount	0.0	0.0
Debt Issuance Costs	(0.1)	(0.1)
Book Value	$ 25.9	$ 26.8
Effective Interest Rate	7.90%	7.90%
Unsecured Second A&R CDA
Debt Instrument [Line Items]
Par Value	$ 45.2	$ 46.7
Discount	0.0	0.0
Debt Issuance Costs	(0.1)	(0.2)
Book Value	$ 45.1	$ 46.5
Effective Interest Rate	7.90%	7.90%
Par Value, Current Maturities	$ (1.4)	$ (1.5)
Discount, Current Maturities	0.0	0.0
Deferred Issuance Costs, Current	0.0	0.0
Book Value, Current Maturities	(1.4)	(1.5)
Lease financing obligations
Debt Instrument [Line Items]
Par Value	231.6	242.7
Discount	0.0	0.0
Debt Issuance Costs	(0.3)	(0.5)
Book Value	$ 231.3	$ 242.2
Effective Interest Rate	16.50%	14.90%
Par Value, Current Maturities	$ (2.7)	$ (5.0)
Discount, Current Maturities	0.0	0.0
Deferred Issuance Costs, Current	0.0	0.0
Book Value, Current Maturities	$ (2.7)	(5.0)
Prior Term Loan
Debt Instrument [Line Items]
Par Value		573.7
Discount		(7.8)
Debt Issuance Costs		(6.5)
Book Value		$ 559.4
Effective Interest Rate		11.40%
Par Value, Current Maturities		$ (14.2)
Discount, Current Maturities		0.0
Deferred Issuance Costs, Current		0.0
Book Value, Current Maturities		$ (14.2)