Equity - Issue and Conversion (Details) - USD ($)	1 Months Ended		6 Months Ended
	Dec. 31, 2016	May 31, 2016	Jun. 30, 2017	Jun. 30, 2016
Proceeds from issuance of common stock			$ 674,000	$ 3,599,000
ATM Agreement
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
Equity issue costs	$ 109,000
Common stock issued (in shares)			1,011,000
Sale price (in dollars per shares)			$ 0.70
Gross proceeds from common stock sale			$ 712,000
Commission payment			16,000
Amortization of deferred cost			22,000
Proceeds from issuance of common stock			674,000
ATM Agreement | General and administrative costs
Equity issue costs			$ 15,000
Registered Offering
Equity issue costs		$ 4,000,000
Common stock issued (in shares)		8,000,000
Sale price (in dollars per shares)		$ 0.50