Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Total revenues	$ 1,106.0	$ 782.4	$ 560.9
Operating expenses:
Cost of product sales and contract development and manufacturing services	433.5	322.3	187.7
Research and development	226.2	142.8	97.4
Selling, general and administrative	273.5	202.5	142.9
Amortization of intangible assets	58.7	25.0	8.6
Total operating expenses	991.9	692.6	436.6
Income from operations	114.1	89.8	124.3
Other income (expense):
Interest expense	(38.4)	(9.9)	(6.6)
Other income (expense), net	1.7	1.6	0.9
Total other income (expense), net	(36.7)	(8.3)	(5.7)
Income before provision for income taxes	77.4	81.5	118.6
Provision for income taxes	22.9	18.8	36.0
Net income	$ 54.5	$ 62.7	$ 82.6
Net income per share-basic (in dollars per share)	$ 1.06	$ 1.25	$ 1.98
Net income per share-diluted (in dollars per share)	$ 1.04	$ 1.22	$ 1.71
Weighted-average number of shares - basic (in shares)	51.5	50.1	41.8
Weighted-average number of shares - diluted (in shares)	52.4	51.4	50.3
Product sales, net
Revenues:
Total revenues	$ 903.5	$ 606.5	$ 421.5
Contract development and manufacturing services
Revenues:
Total revenues	80.0	98.9	68.9
Contracts and grants
Revenues:
Total revenues	$ 122.5	$ 77.0	$ 70.5