Goodwill and Other Intangible Assets - Intangible Assets and Amortization Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Finite-Lived Intangible Assets
Gross carrying amount	$ 92.1		$ 92.1		$ 92.1
Accumulated amortization	45.9		45.9		36.1
Unamortized intangible assets, gross carrying amount	35.7		35.7		35.7
Intangible assets, net	81.9		81.9		91.7
Amortization expense	3.3	$ 1.8	9.8	$ 5.3
Q4 2018	3.2		3.2
2019	13.0		13.0
2020	7.7		7.7
2021	7.1		7.1
2022	7.0		7.0
Trademarks
Finite-Lived Intangible Assets
Unamortized intangible assets, gross carrying amount	32.0		32.0		32.0
In Process Research and Development [Member]
Finite-Lived Intangible Assets
Unamortized intangible assets, gross carrying amount	3.7		3.7		3.7
Trademarks
Finite-Lived Intangible Assets
Gross carrying amount	1.0		1.0		1.0
Accumulated amortization	0.3		0.3		0.2
Patents
Finite-Lived Intangible Assets
Gross carrying amount	40.8		40.8		40.8
Accumulated amortization	35.0		35.0		31.5
Customer relationships
Finite-Lived Intangible Assets
Gross carrying amount	12.0		12.0		12.0
Accumulated amortization	4.9		4.9		3.6
0
Finite-Lived Intangible Assets
Gross carrying amount	36.5		36.5		36.5
Accumulated amortization	5.2		5.2		0.7
Non-competition agreements
Finite-Lived Intangible Assets
Gross carrying amount	1.8		1.8		1.8
Accumulated amortization	$ 0.5		$ 0.5		$ 0.1