Condensed Consolidated Statements of Income (Loss) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Total revenues	$ 2,964.7	$ 2,645.6	$ 5,734.9	$ 5,336.2
Costs and expenses:
Cost of sales	407.5	371.9	770.5	714.5
Research and development expenses	978.4	966.6	1,958.1	1,755.7
Acquired in-process research and development expenses	2.2	4,449.1	22.0	4,525.9
Selling, general and administrative expenses	424.6	372.2	821.0	714.9
Intangible asset impairment charge	0.0	0.0	379.0	0.0
Change in fair value of contingent consideration	0.9	0.5	3.1	0.4
Total costs and expenses	1,813.6	6,160.3	3,953.7	7,711.4
Income (loss) from operations	1,151.1	(3,514.7)	1,781.2	(2,375.2)
Interest income	122.4	156.5	243.3	337.7
Interest expense	(3.7)	(9.9)	(6.7)	(20.3)
Other income (expense), net	13.2	(23.1)	(4.4)	(54.3)
Income (loss) before provision for income taxes	1,283.0	(3,391.2)	2,013.4	(2,112.1)
Provision for income taxes	250.1	202.4	334.2	381.9
Net income (loss)	$ 1,032.9	$ (3,593.6)	$ 1,679.2	$ (2,494.0)
Net income (loss) per common share:
Basic (in dollars per share)	$ 4.02	$ (13.92)	$ 6.54	$ (9.66)
Diluted (in dollars per share)	$ 3.99	$ (13.92)	$ 6.48	$ (9.66)
Shares used in per share calculations:
Basic (in shares)	256.7	258.1	256.8	258.1
Diluted (in shares)	258.9	258.1	259.2	258.1
Product revenues, net
Total revenues	$ 2,944.0	$ 2,645.6	$ 5,704.2	$ 5,336.2
Other revenues
Total revenues	$ 20.7	$ 0.0	$ 30.7	$ 0.0