Quarterly Financial Information (Unaudited) - Selected Quarter Data (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Quarterly Financial Information [Line Items]
Net product revenues	$ 6,129,123	$ 5,620,889	$ 7,361,829	$ 3,118,632	$ 5,441,467	$ 4,129,112	$ 4,942,085	$ 3,464,944	$ 22,230,473	$ 17,977,608	$ 27,046,730
Royalties	927,655	1,017,609	834,211	680,377	900,754	782,694	686,719	600,813	3,459,852	2,970,980	1,252,382
Other revenues	34,484	34,540	34,496	34,532	34,648	34,888	13,615,315	8,428,582	138,052	22,113,433	17,377,185
Net revenues	7,091,262	6,673,038	8,230,536	3,833,541	6,376,869	4,946,694	19,244,119	12,494,339	25,828,377	43,062,021	45,676,297
Gross profit	3,958,622	3,486,246	3,764,690	1,830,555	2,846,714	1,822,410	16,242,031	10,459,501	13,040,113	31,370,656	36,655,396
Operating Expenses	2,997,499	2,045,675	2,082,428	3,105,003	2,131,223	2,045,675	504,975	3,759,921	10,230,605	8,441,794	35,481,603
Income (loss) from operations	961,123	1,440,571	1,682,262	(1,274,448)	1,087,316	(595,090)	15,737,056	6,699,580	2,809,508	22,928,862	1,173,793
Unrealized gain (loss) on stock warrants					(2,233,675)	5,050,520	2,797,928	(7,779,316)		(2,164,543)
Unrealized gain (loss) on stock warrants	1,595,530	(1,065,498)	205,700	6,259,367					6,995,099	556,662	(5,229,089)
Net income (loss)	$ 2,631,341	$ 388,729	$ 1,942,810	$ 4,954,393	$ (1,017,357)	$ 4,417,241	$ 18,314,195	$ (1,186,887)	$ 9,917,273	$ 20,527,192	$ (21,830,682)
Earnings Per Share [Abstract]
Earnings Per Share, Basic	$ 0.03	$ 0.00	$ 0.02	$ 0.06	$ (0.01)	$ 0.05	$ 0.21	$ (0.01)	$ 0.11	$ 0.24	$ (0.30)
Diluted (in dollars per share)	$ 0.01	$ 0.00	$ 0.02	$ (0.02)	$ (0.01)	$ (0.01)	$ 0.16	$ (0.01)	$ 0.03	$ 0.22	$ (0.30)
Minimum [Member]
Market Price Per Share [Abstract]
Stock Price	$ 1.23	$ 1.15	$ 0.77	$ 2.96	$ 2.74	$ 3.39	$ 4.31	$ 4.09	$ 1.23	$ 2.74
Maximum [Member]
Market Price Per Share [Abstract]
Stock Price	$ 0.55	$ 0.68	$ 0.61	$ 0.62	$ 1.78	$ 1.92	$ 2.90	$ 2.07	$ 0.55	$ 1.78