Other Consolidated Financial Statement Detail (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Other Income (Expense), Net
Interest income	$ (80.9)	$ (2.9)
Interest expense	62.5	66.1
(Gains) losses on investments, net	77.7	191.1
Foreign exchange (gains) losses, net	10.7	8.3
Other, net	(0.6)	0.7
Other (income) expense	69.4	263.3
Equity Securities, FV-NI, Gain (Loss), Alternative [Abstract]
Net (gains) losses recognized on equity securities	78.1	190.7
Less: Net (gains) losses realized on equity securities	1.6	(0.2)
Net unrealized (gains) losses recognized on equity securities	76.5	190.9
Accrued Expenses and Other
Revenue-related reserves for discounts and allowances	1,045.0		$ 1,035.0
Collaboration expense	187.2		395.6
Royalties and licensing fees	183.9		209.4
Collaboration expense	265.5		277.9
Other	744.4		746.9
Total accrued expense and other	2,288.2		2,521.4
Ionis, Sangamo, Denali and Sage
Equity Securities, FV-NI, Gain (Loss), Alternative [Abstract]
Net unrealized (gains) losses recognized on equity securities	100.0	$ 205.5
Component of accrued expenses and other
Accrued Expenses and Other
Revenue-related reserves for discounts and allowances	$ 907.2		$ 891.6