Supplemental Guarantor Information - Condensed Consolidating Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	$ 146.4	$ 158.7	$ 290.8	$ 222.9
Consolidating Adjustments
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	(342.3)	(357.0)	(678.9)	(556.6)
Parent Guarantor | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	146.4	158.7	290.8	222.9
Subsidiary Issuer | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	146.5	158.7	291.0	222.9
Guarantor Subsidiaries | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	207.9	171.4	372.8	291.4
Non-Guarantor Subsidiaries | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	(12.1)	26.9	15.1	42.3
Co-Issuer | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	$ 0.0	$ 0.0	$ 0.0	$ 0.0