Other Consolidated Financial Statement Detail - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Business Combination [Line Items]
Litigation related expense	$ 139.5	$ 26.3	$ 3.9
Net unrealized (gains) losses recognized on equity securities	18.2	102.4	270.0
Prepaid taxes	693.6	307.2
Other long-term liabilities	748.5	732.3
Accrued income taxes	166.4	156.7
Denali Therapeutics
Business Combination [Line Items]
Net unrealized (gains) losses recognized on equity securities	27.7
Sage Therapeutics
Business Combination [Line Items]
Net unrealized (gains) losses recognized on equity securities	$ 23.0	(101.4)
Denali And Sangamo
Business Combination [Line Items]
Net unrealized (gains) losses recognized on equity securities		$ 7.5
Ionis, Sangamo, Denali and Sage
Business Combination [Line Items]
Net unrealized (gains) losses recognized on equity securities			$ (248.5)