CONDENSED CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenues:
Total revenues	$ 590.2	$ 452.7	$ 1,105.5	$ 873.1
Operating expenses:
Cost of revenues	9.2	11.5	16.7	20.0
Research and development	191.1	145.8	350.5	285.3
Acquired in-process research and development	2.5	0.0	8.5	143.9
Selling, general and administrative	242.0	221.8	485.1	464.5
Total operating expenses	444.8	379.1	860.8	913.7
Operating income (loss)	145.4	73.6	244.7	(40.6)
Other (expense) income:
Unrealized (loss) gain on equity securities	(19.9)	37.3	(18.3)	39.5
Charges associated with convertible senior notes	(49.7)	0.0	(138.4)	0.0
Investment income and other, net	22.8	10.7	45.1	19.4
Total other (expense) income, net	(46.8)	48.0	(111.6)	58.9
Income before provision for income taxes	98.6	121.6	133.1	18.3
Provision for (benefit from) income taxes	33.6	26.1	24.7	(0.6)
Net income	65.0	95.5	108.4	18.9
Foreign currency translation adjustments, net of tax	0.1	0.9	(0.4)	2.1
Unrealized (loss) gain on debt securities available-for-sale, net of tax	(0.9)	0.7	(4.1)	4.7
Comprehensive income	$ 64.2	$ 97.1	$ 103.9	$ 25.7
Earnings per share:
Basic (in USD per share)	$ 0.64	$ 0.98	$ 1.08	$ 0.19
Diluted (in USD per share)	$ 0.63	$ 0.95	$ 1.04	$ 0.19
Weighted-average shares outstanding:
Basic (in shares)	100.8	97.6	100.3	97.4
Diluted (in shares)	103.9	100.2	103.8	100.3
Net product sales
Revenues:
Total revenues	$ 583.8	$ 446.3	$ 1,092.8	$ 861.6
Collaboration revenues
Revenues:
Total revenues	$ 6.4	$ 6.4	$ 12.7	$ 11.5