Other Post-Employment Benefits and Other Employee Benefit Plans - Components of Net Periodic Benefit Cost (Details) - Other Post-Employment Benefits and Other Employee Benefit Plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components of net periodic benefit cost:
Service cost	$ 0.0	$ 0.0	$ 0.1
Interest cost	1.0	1.6	1.4
Amortization of net gain	(0.2)	(0.2)	(0.2)
Amortization of prior service credit	(0.3)	(0.3)	(0.3)
Net periodic benefit cost	0.5	1.1	1.0
Impact of settlement/curtailment	0.0	0.0	0.0
Total benefit cost (income)	$ 0.5	$ 1.1	$ 1.0