Restructurings (Details) $ in Millions		1 Months Ended	3 Months Ended	9 Months Ended
	Feb. 27, 2020 position	Aug. 31, 2020 position	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Restructuring Costs
Restructuring costs			$ 3.0	$ 4.8
Selling, general and administrative expenses
Restructuring Costs
Restructuring costs			2.9	4.3
Research and development expense.
Restructuring Costs
Restructuring costs			$ 0.1	$ 0.5
February 2020 Restructuring | One-time Termination Benefits
Restructuring Costs
Number of eliminated positions | position	31
August 2020 Restructuring | One-time Termination Benefits
Restructuring Costs
Number of eliminated positions | position		41