Long-term Debt and Other Financing Debt Notes (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Unamortized debt discount and issuance costs	$ (31.1)	$ (41.7)
Total long-term debt	1,969.7	1,993.7
Senior Secured Notes Due July 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 380.0	$ 380.0
Debt Instrument, Interest Rate, Stated Percentage	7.50%	7.50%
Debt Instrument, Interest Rate, Effective Percentage	8.30%	8.30%
Exchangeable Senior Notes Due November 2019 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 148.5	$ 148.5
Debt Instrument, Interest Rate, Stated Percentage	5.00%	5.00%
Debt Instrument, Interest Rate, Effective Percentage	10.80%	10.80%
Senior Notes Due October 2021 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 406.2	$ 406.2
Debt Instrument, Interest Rate, Stated Percentage	7.625%	7.625%
Senior Notes Due October 2025 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 270.2	$ 274.8
Debt Instrument, Interest Rate, Stated Percentage	6.375%	6.375%
Debt Instrument, Interest Rate, Effective Percentage	7.10%	7.10%
Debt Instrument, Repurchase Amount	$ 4.6
Senior Notes Due March 2027 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 391.6	$ 391.6
Debt Instrument, Interest Rate, Stated Percentage	7.00%	7.00%
Industrial Revenue Bonds [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 99.3	$ 99.3
Industrial Revenue Bonds due in 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	7.3
Other Nonoperating Income (Expense) [Member] \| Senior Notes Due October 2025 [Member]
Debt Instrument [Line Items]
Gain (Loss) on Repurchase of Debt Instrument	$ 0.6

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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