STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning Balance, shares at Dec. 31, 2014		3,021,498
Beginning Balance at Dec. 31, 2014	$ 14,741	$ 3	$ 99,360		$ (84,622)
Issuance of common stock for cash, net of offering costs, shares		6,003,082
Issuance of common stock for cash, net of offering costs	34,175	$ 6	34,169
Issuance of common stock upon vesting of Restricted Stock Units, shares		26,669
Issuance of common stock upon vesting of Restricted Stock Units, value	0	$ 0	0	$ 0	0
Adjustment for fractional shares		(32)
Share-based compensation	599		599
Net loss	$ (11,445)				(11,445)
Ending Balance, shares at Dec. 31, 2015	9,051,217	9,051,217
Ending Balance at Dec. 31, 2015	$ 38,070	$ 9	134,128		(96,067)
Issuance of common stock upon vesting of Restricted Stock Units, shares		5,430
Issuance of common stock upon vesting of Restricted Stock Units, value	0	$ 0	0	0	0
Share-based compensation	155		155
Change in unrealized gain on marketable securities	6			6
Net loss	$ (3,647)				(3,647)
Ending Balance, shares at Mar. 31, 2016	9,056,647	9,056,647
Ending Balance at Mar. 31, 2016	$ 34,584	$ 9	$ 134,283	$ 6	$ (99,714)