Financial Information for Guarantor Subsidiaries and Non-Guarantor Subsidiaries - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Mar. 31, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Parent company's percentage ownership of guarantors (as a percent)	100.00%		100.00%
Assets	$ 8,615.1		$ 8,615.1		$ 9,995.2
Liabilities	9,595.9		9,595.9		9,991.3
Net loss from Consolidated Statements of Operations and Comprehensive Loss	(678.2)	$ (69.8)	(866.8)	$ (187.2)
Net cash provided by (used in) operating activities			255.5	233.4
Guarantor Subsidiaries
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Assets	6,228.5		6,228.5		7,397.0
Net loss from Consolidated Statements of Operations and Comprehensive Loss	(819.9)	(42.9)	(1,040.4)	(91.7)
Net cash provided by (used in) operating activities			85.2	160.0
Non-Guarantor Subsidiaries
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Assets	2,160.9		2,160.9		$ 2,505.4
Net loss from Consolidated Statements of Operations and Comprehensive Loss	$ (61.6)	23.0	(35.0)	83.2
Net cash provided by (used in) operating activities			$ 137.5	132.8
Restatement Adjustment | Guarantor Subsidiaries
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Assets		546.0		546.0
Liabilities		466.3		466.3
Stockholders liability		1.1		1.1		$ 1.7
Restatement Adjustment | Non-Guarantor Subsidiaries
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Assets		$ 11.3		$ 11.3		$ 3.8