Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues
Revenues	$ 7,881	$ 40,031	$ 8,765	$ 172,422
Type of Revenue [Extensible List]	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember
Operating Expenses
Cost of revenues	$ 1,927	$ 3,872	$ 1,956	$ 6,280
Research and development	29,483	21,486	54,686	41,036
General and administrative	13,405	8,318	24,963	16,698
Total operating expenses	44,753	33,681	81,543	64,047
Other operating expenses (income)	(62)	5	(62)	33
Income (loss) from operations	(36,872)	6,350	(72,778)	108,375
Other Income
Interest income from licensing	762	6,898	1,375	8,253
Investment income	34,524	1,196	37,519	2,055
Total other income	35,286	8,094	38,894	10,308
Income (loss) before income taxes	(1,586)	14,444	(33,884)	118,683
Income Tax Benefit (Expense)	129	(3,850)	199	(3,850)
Net income (loss)	(1,457)	10,594	(33,685)	114,833
Other Comprehensive Income (Loss)
Unrealized gain (loss) on available-for-sale securities, net of reclassifications and income tax expense	530	132	1,151	(56)
Total other comprehensive income (loss)	530	132	1,151	(56)
Comprehensive income (loss)	(927)	10,726	(32,534)	114,777
Net income (loss) applicable to common stockholders	$ (1,457)	$ 10,594	$ (33,685)	$ 114,833
Net income (loss) per share:
Basic	$ (0.04)	$ 0.33	$ (0.92)	$ 3.60
Diluted	$ (0.04)	$ 0.30	$ (0.92)	$ 3.29
Weighted-average common shares outstanding:
Basic	36,669	32,082	36,518	31,858
Diluted	36,669	35,272	36,518	34,884