Financial Information for Guarantor Subsidiaries and Non-Guarantor Subsidiaries - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 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	$ 9,486.5		$ 9,486.5		$ 9,995.2
Liabilities	9,746.6		9,746.6		9,991.3
Net loss from Consolidated Statements of Operations and Comprehensive Loss	(102.2)	$ (72.4)	(188.6)	$ (117.4)
Net cash provided by (used in) operating activities			114.4	107.1
Guarantor Subsidiaries
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Assets	7,106.4		7,106.4		7,397.0
Net loss from Consolidated Statements of Operations and Comprehensive Loss	(86.7)	(44.0)	(220.5)	(48.8)
Net cash provided by (used in) operating activities			127.7	62.7
Non-Guarantor Subsidiaries
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Assets	2,323.4		2,323.4		$ 2,505.4
Net loss from Consolidated Statements of Operations and Comprehensive Loss	$ 21.0	30.2	26.6	60.1
Net cash provided by (used in) operating activities			$ 89.2	90.2
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		0.6		0.6		$ 0.1
Restatement Adjustment | Non-Guarantor Subsidiaries
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Assets		$ 7.6		$ 7.6		$ 3.5