CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenues:
Revenue from collaborative research	$ 78,497	$ 5,598	$ 80,390	$ 76,763
Revenue from government agreements	2,176	1,118	3,129	1,232
Total revenues	80,673	6,716	83,519	77,995
Costs and expenses:
Research and development	33,340	22,660	60,686	44,124
General and administrative	7,239	5,346	13,372	10,029
Total costs and expenses	40,579	28,006	74,058	54,153
Income (loss) from operations	40,094	(21,290)	9,461	23,842
Other income (expense)	370	(86)	640	(89)
Net income (loss)	40,464	(21,376)	10,101	23,753
Other comprehensive income (loss):
Unrealized gain (loss) on investments	7	0	64	0
Comprehensive income (loss)	$ 40,471	$ (21,376)	$ 10,165	$ 23,753
Basic net income (loss) per common share (in dollars per share)	$ 1.17	$ (0.71)	$ 0.29	$ 0.80
Diluted net income (loss) per common share (in dollars per share)	$ 1.12	$ (0.71)	$ 0.28	$ 0.75
Basic weighted average number of common shares (in shares)	34,616,197	30,059,329	34,560,021	29,739,326
Diluted weighted average number of common shares (in shares)	36,017,411	30,059,329	35,966,987	31,797,332