Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (48.7)	$ (78.6)	$ (172.9)	$ (245.6)
Other comprehensive income (loss), net of tax:
Designated hedge gains (losses)	4.6	1.8	26.2	(12.3)
Defined benefit plan actuarial gains	0.1	0.1	0.2	0.3
Foreign currency translation	(12.4)	13.2	(38.0)	53.6
Total other comprehensive (loss) income	(7.7)	15.1	(11.6)	41.6
Total comprehensive loss	$ (56.4)	$ (63.5)	$ (184.5)	$ (204.0)