Equity (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reconciliation of equity attributable to non-controlling interests
NCI, beginning of period	$ (16.2)	$ (11.6)	$ (14.7)	$ (11.5)
Net income (loss) attributable to NCI, net of tax	48.4	0.0	46.7	(0.1)
Capital contribution by noncontrolling interest	11.1	0.0	11.1	0.0
Distribution to noncontrolling interest	(50.0)	0.0	(50.0)	0.0
Translation adjustment and other	(0.5)	0.0	(0.3)	0.0
NCI, end of period	$ (7.2)	$ (11.6)	$ (7.2)	$ (11.6)