Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Revenue:
Product revenue	$ 14,334,687	$ 11,934,269
Royalty and other revenue	1,991,166	4,521,724
Total revenue	16,325,853	16,455,993
Operating expenses:
Cost of product revenue	6,335,064	6,896,608
Cost of royalty revenue		576,857
Research and development	1,200,990	2,183,404
Selling, general and administrative	3,383,610	3,308,099
Contingent consideration - fair value adjustments	98,320	(53,974)
Total operating expenses	11,017,984	12,910,994
Income from operations	5,307,869	3,544,999
Investment income	101,816	61,519
Interest expense	(14,085)	(13,531)
Other income	2,505	29,081
Income before income taxes	5,398,105	3,622,068
Income tax provision	1,121,002	1,283,832
Net income	4,277,103	2,338,236
Earnings per share:
Basic	$ 0.13	$ 0.07
Diluted	$ 0.13	$ 0.07
Weighted average shares outstanding:
Basic	31,962,843	31,240,606
Diluted	32,831,019	31,855,428
Other comprehensive income:
Unrealized gain (loss) on investments	2,184	(1,983)
Foreign currency translation loss	(143,153)	(256,608)
Comprehensive income	$ 4,136,134	$ 2,079,645