Severance and Retention Costs, Restructured North American TEGSEDI Operations (Details) - Restructured North American TEGSEDI Operations [Member] $ in Millions	3 Months Ended
	Jun. 30, 2021 USD ($)
Severance and Retention Costs [Abstract]
Beginning balance	$ 0.0
Amounts expensed during the period	9.4
Amounts paid during the period	(7.6)
Ending balance	1.8
Research, Development and Patent Expenses [Member]
Severance and Retention Costs [Abstract]
Amounts expensed during the period	2.3
Selling, General and Administrative Expenses [Member]
Severance and Retention Costs [Abstract]
Amounts expensed during the period	$ 7.1