Investments in Affiliates (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Jun. 30, 2015
Schedule of Equity Method Investments [Line Items]
Revenue	$ 74.3	$ 76.4		$ 143.9	$ 208.0
Gross profit	25.5	21.4		48.5	28.3
Net income (loss)	8.7	5.8		16.5	(18.8)
Impairment of Magnetation investment	$ 0.0	0.0		$ 0.0	256.3
Magnetation LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	49.90%			49.90%
Impairment of Magnetation investment			$ 256.3
Cost of Sales [Member]
Schedule of Equity Method Investments [Line Items]
Income (Loss) from Equity Method Investments	$ 3.4	$ 1.8		$ 6.3	3.6
Other Nonoperating Income (Expense) [Member]
Schedule of Equity Method Investments [Line Items]
Income (Loss) from Equity Method Investments					$ (16.3)