CONDENSED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) (USD $)	Total	Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2011	$ (11,423,231)	$ 5,000	$ 36,710	$ 91,111,640	$ (102,576,581)
Beginning Balance (in shares) at Dec. 31, 2011		5,000,000	36,709,706
Net loss	(3,930,765)	0	0	0	(3,930,765)
Private placement of preferred stock, net of offering costs (in shares)		500,000	0
Private placement of preferred stock, net of offering costs	2,613,970	500	0	2,613,470	0
Warrants issued in connection with private placement of preferred stock	104,907	0	0	104,907
Conversion of convertible debt	0
Common stock issued:
Employee stock purchase plan (in shares)		0	52,158
Employee stock purchase plan	8,810	0	52	8,758	0
Stock-based compensation expense	170,875	0	0	170,875	0
Ending Balance at Sep. 30, 2012	(12,455,434)	5,500	36,762	94,009,650	(106,507,346)
Ending Balance (in shares) at Sep. 30, 2012		5,500,000	36,761,864
Beginning Balance at Dec. 31, 2012	(13,623,800)	5,500	36,762	94,030,603	(107,696,665)
Beginning Balance (in shares) at Dec. 31, 2012		5,500,000	36,761,864
Net loss	(5,153,948)	0	0	0	(5,153,948)
Private placement of preferred stock, net of offering costs (in shares)		0	43,715,847
Private placement of preferred stock, net of offering costs	11,308,920	0	43,716	11,265,204	0
Conversion of preferred stock (in shares)		(5,500,000)	39,089,161
Conversion of preferred stock	0	(5,500)	39,089	(33,589)	0
Conversion of convertible debt (in shares)		0	2,521,222
Conversion of convertible debt	14,316,255	0	2,521	14,313,734	0
Common stock issued:
Exercise of employee stock options (in shares)		0	252,000
Exercise of employee stock options	80,520	0	252	80,268	0
Cancellation of restricted stock ( in shares)		0	(2,500)
Cancellation of restricted stock	0	0	(2)	2	0
Employee stock purchase plan (in shares)		0	79,496
Employee stock purchase plan	23,232	0	79	23,153	0
Stock-based compensation expense	84,608	0	0	84,608	0
Ending Balance at Sep. 30, 2013	$ 7,035,787	$ 0	$ 122,417	$ 119,763,983	$ (112,850,613)
Ending Balance (in shares) at Sep. 30, 2013		0	122,417,090