Long-term Employee Benefits - Schedule of Net Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net periodic benefit cost:
Service cost	$ 2.1	$ 2.6	$ 4.2	$ 5.1
Interest cost	3.3	3.9	6.7	7.8
Expected return on plan assets	(3.5)	(3.4)	(7.0)	(6.6)
Amortization of actuarial loss, net	0.3	0.2	0.8	0.1
Net periodic benefit (gain) cost	$ 2.2	$ 3.3	$ 4.7	$ 6.4