Other (Expense) Income, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Income and Expenses [Abstract]
Loss on debt extinguishments	$ (72.3)	$ (11.3)	$ 0.0
Loss on derivative contracts	(9.5)	(12.5)	(74.0)
Non-cash change in fair value of preferred stock redemption liability	0.0	(5.0)	0.0
Gain on settlement agreement related to Series B Convertible Preferred Stock	0.0	103.0	0.0
Legal settlements	10.8	0.0	17.7
Sale of intellectual property and product rights	2.2	4.4	6.1
Other income, net	7.6	9.7	6.6
Total	$ (61.2)	$ 88.3	$ (43.6)