Other Expense (Income) - Other Items (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Jun. 30, 2013
Development And Licensing Income [Line Items]
Cost investment impairment	$ 2.2
Deferred income	45.1		$ 57.1
Smart Dose
Development And Licensing Income [Line Items]
Development and licensing income	0.2	$ 0.2
Deferred income	$ 4.5			$ 20.0