CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues:
Total revenues	$ 362.6	$ 389.2
Operating expenses:
Cost of product sales	29.1	53.2
Research and development	897.4	35.7
Selling, general and administrative	92.0	(6.6)
Total operating expenses	1,018.5	82.3
Operating (loss) income	(655.9)	306.9
Other income (expense):
Interest income	9.8	5.3
Interest expense	(10.3)	(2.6)
Other, net	5.8	(0.6)
Total other income, net	5.3	2.1
(Loss) income before income taxes	(650.6)	309.0
Income tax benefit (expense)	156.0	(64.5)
Net (loss) income	$ (494.6)	$ 244.5
Net (loss) income per common share:
Basic (in dollars per share)	$ (11.32)	$ 5.65
Diluted (in dollars per share)	$ (11.32)	$ 5.57
Weighted average number of common shares outstanding:
Basic (in shares)	43.7	43.3
Diluted (in shares)	43.7	43.9
Net product sales
Revenues:
Total revenues	$ 362.6	$ 389.2