Collaborative and Other Relationships - Summary of Activity Related to the UCB Collaboration (Details) - Research and development - UCB Pharma S.A. - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Collaborative arrangements and non-collaborative arrangement transactions
Expense incurred by the collaboration	$ 14.3	$ 15.6	$ 32.6	$ 33.2
Expense reflected within statements of income	$ 7.1	$ 7.8	$ 16.3	$ 16.6