CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues:
Product revenue, net	$ 29,166,658	$ 30,897,444	$ 87,907,894	$ 72,183,782
Revenue, Product and Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Revenues from collaborative arrangements	$ 150,000		$ 150,000
Total revenues	29,316,658	$ 30,897,444	88,057,894	$ 72,183,782
Operating costs and expenses:
Cost of sales	$ 3,878,760	$ 4,387,461	$ 12,169,499	$ 10,360,874
Cost, Product and Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Research and development	$ 3,749,233	$ 4,597,039	$ 12,321,687	$ 12,534,362
Selling, general and administrative	9,984,961	8,067,792	30,881,367	25,471,974
Total operating costs and expenses	17,612,954	17,052,292	55,372,553	48,367,210
Operating income (loss)	11,703,704	13,845,152	32,685,341	23,816,572
Other income, net	33,567	393,415	481,069	1,187,091
Net income (loss) before income taxes	11,737,271	14,238,567	33,166,410	25,003,663
Income tax provision (benefit)	(31,602,596)	608,388	(30,379,459)	1,058,039
Net income (loss)	$ 43,339,867	$ 13,630,179	$ 63,545,869	$ 23,945,624
Net income (loss) per share:
Basic	$ 0.42	$ 0.13	$ 0.61	$ 0.23
Diluted	$ 0.41	$ 0.13	$ 0.60	$ 0.23
Weighted average shares outstanding:
Basic	103,535,431	102,974,105	103,452,025	102,864,571
Diluted	106,316,241	107,045,234	106,386,617	105,821,609
Net income (loss)	$ 43,339,867	$ 13,630,179	$ 63,545,869	$ 23,945,624
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities	(5,280)	(2,330)	(15,976)	39,676
Comprehensive income (loss)	$ 43,334,587	$ 13,627,849	$ 63,529,893	$ 23,985,300