Goodwill and Intangible Assets - Intangible Assets by Major Class (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Schedule of Intangible Assets by Major Class [Line Items]
Cost	$ 83.2	$ 78.1
Accumulated Amortization	(52.7)	(48.3)
Net	30.5	29.8
Patents and licensing
Schedule of Intangible Assets by Major Class [Line Items]
Cost	25.9	21.5
Accumulated Amortization	(17.9)	(16.0)
Net	8.0	5.5
Technology
Schedule of Intangible Assets by Major Class [Line Items]
Cost	3.3	3.3
Accumulated Amortization	(1.7)	(1.5)
Net	1.6	1.8
Trademarks
Schedule of Intangible Assets by Major Class [Line Items]
Cost	2.0	2.0
Accumulated Amortization	(1.8)	(1.8)
Net	0.2	0.2
Customer relationships
Schedule of Intangible Assets by Major Class [Line Items]
Cost	40.9	40.3
Accumulated Amortization	(23.4)	(21.6)
Net	17.5	18.7
Customer contracts
Schedule of Intangible Assets by Major Class [Line Items]
Cost	11.1	11.0
Accumulated Amortization	(7.9)	(7.4)
Net	$ 3.2	$ 3.6