Severance and Retention Costs, Restructured European Operations (Details) - Restructured European Operations [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Severance and Retention Costs [Abstract]
Total estimated expenses	$ 13.6
Remaining estimated expenses to be recognized through October 2021	0.4
Beginning balance	12.4
Amounts expensed during the period	2.2
Reserve adjustments during the period	(1.5)
Net amount expensed during the period	0.7	$ 12.5
Amounts paid during the period	(11.9)
Ending balance	1.2	$ 12.4
R&D Expenses [Member]
Severance and Retention Costs [Abstract]
Net amount expensed during the period	0.1
SG&A Expenses [Member]
Severance and Retention Costs [Abstract]
Net amount expensed during the period	$ 0.6