Statements of Stockholders' Equity - USD ($)	Common Stock [Member]	Additional Paid-in Capital	Accumulated Deficit	Total
Beginning Balance at Dec. 31, 2018	$ 11,000	$ 176,228,000	$ (171,003,000)	$ 5,236,000
Beginning Balance, shares at Dec. 31, 2018	110,942,000
Issuance of common stock for services	$ 0	60,000	0	60,000
Issuance of common stock for services (Shares)	136,000
Stock-based compensation, net	$ 0	28,000	0	28,000
Warrants exercised, net	$ 0	20,000	0	20,000
Warrants exercised, net (Shares)	50,000
Net (loss) income	$ 0	0	(5,812,000)	(5,812,000)
Ending Balance at Mar. 31, 2019	$ 11,000	176,336,000	(176,815,000)	(468,000)
Ending Balance, shares at Mar. 31, 2019	111,128,000
Beginning Balance at Dec. 31, 2019	$ 16,000	191,060,000	(184,633,000)	6,443,000
Beginning Balance, shares at Dec. 31, 2019	158,645,000
Issuance of common stock for services	$ 0	80,000	0	80,000
Issuance of common stock for services (Shares)	136,000
Stock-based compensation, net	$ 0	213,000	0	213,000
Issuance of common stock in connection with the equity distribution agreement	$ 0	682,000	0	682,000
Issuance of common stock in connection with the equity distribution agreement (in shares)	1,241,000
Offering costs related to the issuance of common stock in connection with the equity distribution agreement	$ 0	(246,000)	0	(246,000)
Net (loss) income	0	0	(5,179,000)	(5,179,000)
Ending Balance at Mar. 31, 2020	$ 16,000	$ 191,789,000	$ (189,812,000)	$ 1,993,000
Ending Balance, shares at Mar. 31, 2020	160,022,000