Statements Of Convertible Preferred Stock And Stockholders' Equity - USD ($)	Convertible Preferred Stock [Member] Convertible Preferred Stock [Member]	Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member] Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Common Stock [Member]	Total
Balance, Amount at Dec. 31, 2014			$ 20,481		$ 446,241,703	$ (205,999)	$ (458,605,903)		$ (12,549,718)
Balance, Shares at Dec. 31, 2014			20,480,874
Issuance of common stock, Amount			$ 809		940,545				941,354
Issuance of common stock, Shares			809,822
Share-based compensation					1,312,319				1,312,319
Restricted stock vestings, Amount			$ 242		(242)
Restricted stock vestings, Shares			241,775
Net loss							(7,352,775)		(7,352,775)
Employee stock purchase plan, Amount			$ 19		23,147				23,166
Employee stock purchase plan, Shares			18,702
Balance, Amount at Dec. 31, 2015		$ 0	$ 21,551		448,517,472	(205,999)	(465,958,678)		(17,625,654)
Balance, Shares at Dec. 31, 2015		0	21,551,173
Issuance of common stock, Amount	$ 5,986,081			$ (1,464)				$ (1,464)
Issuance of common stock, Shares	24,000
Share-based compensation					1,365,121				1,365,121
Restricted stock vestings, Amount			$ 318		(318)
Restricted stock vestings, Shares			317,962
Net loss							(5,286,720)		(5,286,720)
Employee stock purchase plan, Amount			$ 39		33,145				33,184
Employee stock purchase plan, Shares			39,008
Beneficial conversion feature of Convertible Preferred Stock		$ (6,145,402)			6,145,402				6,145,402
Deemed dividend related to beneficial conversion feature of Convertible Preferred Stock		6,145,402			(6,145,402)				(6,145,402)
Conversion of Convertible Preferred Stock, Amount		$ (25,606)	$ 156		25,450				25,606
Conversion of Convertible Preferred Stock, Shares		(100)	155,439
Balance, Amount at Dec. 31, 2016		$ 5,960,475	$ 22,064		$ 449,939,406	$ (205,999)	$ (471,245,398)		$ (21,489,927)
Balance, Shares at Dec. 31, 2016		23,900	22,063,582