Equity - Issue and Conversion (Details) - USD ($)						1 Months Ended	6 Months Ended
	Apr. 22, 2020	Apr. 20, 2020	Apr. 09, 2020	Jul. 17, 2019	Jul. 10, 2019	Dec. 31, 2016	Jun. 30, 2020	Jun. 30, 2019	May 09, 2018
Proceeds from issuance of common stock, net of issuance costs							$ 4,079,000	$ 544,000
Warrants Series A and B
Exercise price		$ 0.24
Warrants issued		$ 1,900,000
Expected volatility (as a percent)		95.00%
Risk-free rate (as a percent)		0.41%
Series A Warrants
Warrants Exercise Period				6 months
Exercise price				$ 0.33
Expiration term of warrant				5 years
Warrants issued				$ 2,100,000
Expected volatility (as a percent)				95.00%
Risk-free rate (as a percent)				1.90%
Series B Warrants
Warrants Exercise Period				6 months
Exercise price				$ 0.33
Incremental fair value of warrants				$ 300,000
Expected volatility (as a percent)				88.00%
Risk-free rate (as a percent)				1.90%
Private Placement
Total cost of offering		$ 334,000
Placement agent fee (as a percent)		6.00%
Private Placement | Warrants Series A and B
Share Price		$ 0.30
Aggregate gross proceeds of warrants		$ 3,000,000
ATM Agreement
Proceeds from issuance of common stock, net of issuance costs							$ 223,000
Common stock issued (in shares)							823,452	33,995
Aggregate value of securities allowed under agreement						$ 5,000,000
Aggregate securities allowed under agreement (in shares)						10,000,000
Sale price (in dollars per shares)							$ 0.28	$ 0.34
Gross proceeds from common stock sale								$ 11,000
Commission rate (as a percent)						2.00%
Amortization of deferred cost							$ 8,000
common shares available for issuance							8,100,000
Unamortized deferred cost							$ 129,000
LPC Program [Member]
Proceeds from issuance of common stock, net of issuance costs							$ 216,000
Common stock issued (in shares)							900,000
Sale price (in dollars per shares)							$ 0.27
Amortization of deferred cost							$ 24,000
Total cost of offering				$ 300,000
Placement agent fee (as a percent)				6.00%
Unamortized deferred cost							$ 353,000
LPC Program [Member] | May 2016 Warrants
Exercise price				$ 0.75
LPC Program [Member] | Series A Warrants
Common shares issuable upon exercise				8,653,846
Exercise price				$ 0.35
Aggregate gross proceeds of warrants				$ 2,250,000
LPC Program [Member] | Series B Warrants
Common shares issuable upon exercise				4,500,000
Number of common shares which can be purchased with each warrant				1
Exercise price				$ 0.35
Commitment purchase agreement
Proceeds from issuance of common stock, net of issuance costs								$ 590,000
Common stock issued (in shares)								2,113,642
Aggregate value of securities allowed under agreement									$ 10,000,000
Sale price (in dollars per shares)								$ 0.28
Amortization of deferred cost								$ 58,000
Minimum | Private Placement
Warrants Exercise Period	5 years
Maximum | Private Placement
Warrants Exercise Period	6 years
Common Stock | Private Placement
Share Price		$ 0.20
Common shares issuable upon exercise		11,250,000
Common stock issued (in shares)		15,000,000					15,000,000
Common Stock | Private Placement | Series A Warrants
Common shares issuable upon exercise		7,500,000
Common Stock | Private Placement | Series B Warrants
Common shares issuable upon exercise		3,750,000
Exercise price	$ 0.26
Common Stock | Subscription Agreement
Common stock issued (in shares)							4,719,207
Common Stock | LPC Program [Member]
Share Price				$ 0.26
Common stock issued (in shares)				8,653,846	8,653,846
Common Stock | Maximum | LPC Program [Member] | Series A Warrants
Common stock issued (in shares)				8,653,846
Barrick | Subscription Agreement
Number of shares to purchase in agreement			4,719,207
Purchase price			$ 0.2119
Proceeds from issuance of common stock, net of issuance costs			$ 900,000