Collaborative and Other Relationships - Summary of Activity Related to the UCB Collaboration (Details) - Research and development - UCB Pharma S.A. - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Collaborative arrangements and non-collaborative arrangement transactions
Expense incurred by the collaboration	$ 84.2	$ 58.3	$ 31.9
Expense reflected within statements of income	$ 42.1	$ 29.2	$ 16.0