Collaborative and Other Relationships - Summary of Activity Related to Sage Therapeutics (Details) - Sage Therapeutics - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Research and development
Collaborative arrangements and non-collaborative arrangement transactions
Expense incurred by the collaboration	$ 2.7	$ 34.2	$ 176.7
Expense reflected within statements of income	1.3	17.1	88.3
Selling, general and administrative
Collaborative arrangements and non-collaborative arrangement transactions
Expense incurred by the collaboration	173.0	118.5	187.0
Expense reflected within statements of income	$ 86.5	$ 59.2	$ 93.5