CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended			129 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012
Operating expenses:
Research and development	$ 16,744,423	$ 37,270,138	$ 30,871,125	$ 162,504,846
Sales and marketing	7,221,800	8,067,709	2,476,494	24,246,376
General and administrative	5,679,485	5,276,146	4,154,944	30,903,158
Restructuring	2,157,795	0	0	2,157,795
Total operating expenses	31,803,503	50,613,993	37,502,563	219,812,175
Operating loss	(31,803,503)	(50,613,993)	(37,502,563)	(219,812,175)
Interest income	67,594	161,828	242,883	5,009,113
Interest expense	0	0	(70,389)	(258,348)
Net loss	$ (31,735,909)	$ (50,452,165)	$ (37,330,069)	$ (215,061,410)
Net loss per basic and diluted share of common stock (in dollars per share)	$ (0.47)	$ (0.84)	$ (0.91)
Weighted average number of basic and diluted common shares outstanding (in shares)	66,892,982	60,136,326	41,184,623