Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Revenues	$ 40,031	$ 6,562	$ 172,422	$ 7,017
Costs of revenues
Research and development	21,486	13,917	41,036	30,536
General and administrative	8,318	6,355	16,698	12,977
Other operating expenses	5	29	33	74
Total operating expenses	33,681	21,618	64,047	44,995
Income (loss) from operations	6,350	(15,056)	108,375	(37,978)
Other Income
Interest income from licensing	6,898		8,253
Investment income	1,196	583	2,055	1,512
Total other income	8,094	583	10,308	1,512
Income (loss) before income taxes	14,444	(14,473)	118,683	(36,466)
Income Tax Expense	(3,850)		(3,850)
Net income (loss)	10,594	(14,473)	114,833	(36,466)
Other Comprehensive Income (Loss)
Unrealized gain (loss) on available-for-sale securities, net of reclassifications and income tax expense	132	(74)	(56)	(613)
Total other comprehensive income (loss)	132	(74)	(56)	(613)
Comprehensive income (loss)	10,726	(14,547)	114,777	(37,079)
Net income (loss) applicable to common stockholders	$ 10,594	$ (14,473)	$ 114,833	$ (36,466)
Net income (loss) per share:
Basic	$ 0.33	$ (0.47)	$ 3.60	$ (1.27)
Diluted	$ 0.30	$ (0.47)	$ 3.29	$ (1.27)
Weighted-average common shares outstanding:
Basic	32,082	30,662	31,858	28,678
Diluted	35,272	30,662	34,884	28,678
License [Member]
Revenues
Revenues	$ 40,031	$ 6,555	$ 172,422	$ 7,010
Costs of revenues
Costs of revenues	$ 3,872	1,311	$ 6,280	1,402
Other [Member]
Revenues
Revenues		7		7
Costs of revenues
Costs of revenues		$ 6		$ 6