Stockholders' Equity (Detail Textuals) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended		6 Months Ended
	May 10, 2016	Feb. 11, 2014	Mar. 31, 2014	Mar. 18, 2014	Jun. 30, 2016	Dec. 31, 2015	Jan. 31, 2014
Class of Warrant or Right [Line Items]
Stock issuance maximum limit							$ 75,000
Proceeds from issuance or sale of equity	$ 4,500				$ 5,000
Common stock, par value (in dollars per share)					$ 0.001	$ 0.001
Number of shares sold under registered direct offering	5,471,957
Offering price	$ 0.91375
Registered Direct Offering
Class of Warrant or Right [Line Items]
Number of shares sold under registered direct offering				2,870,000
Offering price				$ 3.15
Value of shares sold under registered direct offering				$ 9,000
Roth Equity Distribution Agreement | Registered Direct Offering
Class of Warrant or Right [Line Items]
Number of shares sold under registered direct offering					9,063,634
Value of shares sold under registered direct offering					$ 16,600
Proceeds of shares sold net of issuance cost					$ 15,200
Roth Equity Distribution Agreement | ATM offering
Class of Warrant or Right [Line Items]
Proceeds from issuance or sale of equity		$ 10,000	$ 2,600
Common stock, par value (in dollars per share)		$ 0.001
Number of shares sold			721,677
Warrant | Investor
Class of Warrant or Right [Line Items]
Proceeds from issuance or sale of equity	$ 5,000
Number of warrants to purchase shares of common stock	4,103,968
Warrant exercise price	$ 0.83
Placement Agent Warrants
Class of Warrant or Right [Line Items]
Number of warrants to purchase shares of common stock	383,037
Warrant exercise price	$ 1.1422