Equity - Issue and Conversion (Details) - USD ($)		1 Months Ended		9 Months Ended
	Aug. 02, 2017	Dec. 31, 2016	May 31, 2016	Sep. 30, 2017	Sep. 30, 2016
Consideration shares sold to Hecla, net				$ 929,000
Proceeds from issuance of common stock				1,611,000	$ 3,599,000
Hecla
Agreement period	2 years
Consideration shares sold to Hecla, net	$ 1,000,000
Consideration shares sold to Hecla, net (in shares)	1,800,000
Sale price (in dollars per shares)	$ 0.55
Volume weighted average stock price period	30 days
Equity issue costs				$ 71,000
ATM Agreement
Sale price (in dollars per shares)				$ 0.70
Equity issue costs		$ 109,000		$ 15,000
Aggregate value of securities allowed under agreement		$ 5,000,000
Aggregate securities allowed under agreement (in shares)		10,000,000
Commission rate (as a percent)		2.00%		2.20%
Legal expenses		$ 50,000
Common stock issued (in shares)				1,024,000
Gross proceeds from common stock sale				$ 720,000
Commission payment				16,000
Amortization of deferred cost				23,000
Proceeds from issuance of common stock				$ 682,000
Registered Offering
Sale price (in dollars per shares)			$ 0.50
Equity issue costs			$ 4,000,000
Common stock issued (in shares)			8,000,000