Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue:
Total revenue	$ 213,312	$ 236,707	$ 189,482
Operating expenses:
Cost of product sales	42,374	33,714	35,785
Cost of royalty revenue	19,542	23,472	19,521
Research and development	44,419	32,607	28,289
Selling, general and administrative	60,509	71,416	53,329
Restructuring charge	7,911	0	0
Gain on sale of asset	0	0	(1,750)
Asset impairment charge	2,704	7,235	0
Change in fair value of contingent consideration	(763)	(7,377)	957
Legal settlement	0	1,650	0
Total operating expenses	176,696	162,717	136,131
Income from operations	36,616	73,990	53,351
Interest income	158	91	84
Interest expense	(2,736)	(1,136)	(8)
Total other (expense) income, net	(2,578)	(1,045)	76
Income before income tax (provision) benefit	34,038	72,945	53,427
Income tax (provision) benefit	(2,135)	(21,002)	28,026
Net income	$ 31,903	$ 51,943	$ 81,453
Earnings per share attributable to common stockholders:
Basic (in dollars per share)	$ 2.16	$ 3.44	$ 5.24
Diluted (in dollars per share)	$ 2.09	$ 3.27	$ 4.96
Weighted average number of common shares outstanding:
Basic (in shares)	14,768,625	15,102,890	15,533,681
Diluted (in shares)	15,278,651	15,908,211	16,434,104
Product sales
Revenue:
Total revenue	$ 70,385	$ 45,327	$ 40,646
Royalty revenue
Revenue:
Total revenue	142,927	153,880	99,040
License and other revenue
Revenue:
Total revenue	$ 0	$ 37,500	$ 49,796