Long-term Employee Benefits - Schedule of Net Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in plan assets and benefit obligations recognized in other comprehensive loss (income):
Net actuarial loss (gain), net	$ 46.1	$ 6.4	$ (31.3)
Pension Plan [Member]
Net periodic benefit cost:
Service cost	7.2	8.8	9.0
Interest cost	13.1	13.1	13.8
Expected return on plan assets	(13.9)	(16.1)	(15.0)
Amortization of actuarial loss, net	1.9	1.3	1.4
Amortization of prior service credit	(0.1)	(0.1)	0.0
Curtailment gain	(2.3)	(0.7)	0.0
Settlement loss	1.1	0.6	0.2
Special termination benefit loss	0.3	0.0	1.0
Net periodic benefit cost	7.3	6.9	10.4
Changes in plan assets and benefit obligations recognized in other comprehensive loss (income):
Net actuarial loss (gain), net	46.7	6.7	(20.6)
Amortization of actuarial loss, net	(1.9)	(1.3)	(1.4)
Prior service cost (credit)	0.0	0.8	(1.2)
Amortization of prior service credit	0.1	0.1	0.0
Curtailment gain	2.3	0.7	0.0
Settlement loss	(1.1)	(0.6)	(0.2)
Other adjustments	0.0	0.0	(7.9)
Total loss (gain) recognized in other comprehensive loss (income)	46.1	6.4	(31.3)
Total recognized in comprehensive loss (income)	$ 53.4	$ 13.3	$ (20.9)