Operating Results of Segments and Reconciliations to Loss Before Income taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Revenues	$ 320.9	$ 368.7	$ 630.3	$ 506.5
Unrealized gains (losses) on derivative financial instruments	1.9	(1.3)	1.5	(1.3)
Segment depreciation and amortization			(25.3)	(13.9)
Amortization of inventories and supplies purchase accounting adjustments			(0.9)	(7.2)
Share-based compensation expense			(1.0)	(0.6)
Other	(0.2)	(1.0)	(1.6)	(1.1)
Operating profit (loss)	8.1	2.8	6.0	(0.4)
Nonoperating expenses	(9.2)	(16.3)	(16.4)	(38.3)
Income tax benefit (expense)	(0.2)	(0.2)	(0.9)	7.2
Earnings from discontinued operations, net of income taxes	0.1	2.9	0.1	27.2
Net loss	(1.2)	(10.8)	(11.2)	(4.3)
Corporate and Other
Segment Reporting Information [Line Items]
Operating loss—excludes share-based compensation expense	(3.1)	(3.8)	(5.9)	(6.7)
Share-based compensation expense	(0.5)	(0.3)	(1.0)	(0.6)
Operating Segments
Segment Reporting Information [Line Items]
Revenues	320.8	368.6	630.2	506.4
Adjusted EBITDA	20.9	22.9	39.2	30.4
Unrealized gains (losses) on derivative financial instruments	1.9	(1.3)	1.5	(1.3)
Segment depreciation and amortization	(10.6)	(10.2)	(25.3)	(13.9)
Amortization of inventories and supplies purchase accounting adjustments	(0.3)	(3.5)	(0.9)	(7.2)
Operating Segments | RANA
Segment Reporting Information [Line Items]
Revenues	212.4	231.0	413.2	316.5
Adjusted EBITDA	14.3	15.9	27.5	20.9
Operating Segments | RAEU
Segment Reporting Information [Line Items]
Revenues	108.4	137.6	217.0	189.9
Adjusted EBITDA	$ 6.6	$ 7.0	$ 11.7	$ 9.5