CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Total revenues	$ 401.5	$ 412.7	$ 1,137.7	$ 1,246.4
Operating expenses:
Cost of product sales	33.0	51.9	88.8	166.8
Research and development	85.7	101.1	1,069.0	219.1
Selling, general and administrative	99.4	110.1	231.0	186.6
Total operating expenses	218.1	263.1	1,388.8	572.5
Operating income (loss)	183.4	149.6	(251.1)	673.9
Interest income	12.1	7.9	32.7	19.9
Interest expense	(11.7)	(4.1)	(34.2)	(9.6)
Other (expense) income, net	(16.9)	(0.9)	19.3	(4.8)
Impairment of investment in privately-held company		(12.4)		(12.4)
Total other (expense) income, net	(16.5)	(9.5)	17.8	(6.9)
Income (loss) before income taxes	166.9	140.1	(233.3)	667.0
Income tax (expense) benefit	(34.5)	(33.6)	76.2	(143.1)
Net income (loss)	$ 132.4	$ 106.5	$ (157.1)	$ 523.9
Net income (loss) per common share:
Basic (in dollars per share)	$ 3.02	$ 2.44	$ (3.59)	$ 12.04
Diluted (in dollars per share)	$ 3.01	$ 2.42	$ (3.59)	$ 11.91
Weighted average number of common shares outstanding:
Basic (in shares)	43.9	43.6	43.8	43.5
Diluted (in shares)	44.0	44.0	43.8	44.0
Net product sales
Revenues:
Total revenues	$ 401.5	$ 412.7	$ 1,137.7	$ 1,246.4