Consolidated Statements of Stockholders` Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at beginning of period at Dec. 31, 2015	$ 437	$ 36	$ 205,377	$ (5,387)	$ (199,589)
Balance at beginning of period (in shares) at Dec. 31, 2015		3,560,000
Increase (decrease) in stockholders' equity
Net loss	(23,474)				(23,474)
Foreign currency translation adjustment	(942)			(942)
Issuance of stock for settlement of accounts payable	184	$ 1	183
Issuance of stock for settlement of accounts payable (in shares)		81,000
Exercise of stock options		5,662,000
Exercise of stock options (in shares)	9,343	$ 56	9,287
Issuance of common stock on conversion of debt	20,038	$ 60	19,978
Issuance of common stock on conversion of debt (in shares)		5,961,000
Exercise of warrants	1,386	$ 4	1,382
Exercise of warrants (in shares)		411,000
Restricted stock unit vesting	0	$ 0	0
Restricted stock unit vesting (in shares)		28,000
Stock-based compensation	1,631		1,631
Balance at end of period at Dec. 31, 2016	$ 8,603	$ 157	237,838	(6,329)	(223,063)
Balance at end of period (in shares) at Dec. 31, 2016	15,703,301	15,703,000
Increase (decrease) in stockholders' equity
Net loss	$ (5,283)				(5,283)
Foreign currency translation adjustment	$ 443			443
Exercise of stock options	18,333	18,000
Exercise of stock options (in shares)	$ 42	$ 0	42
Exercise of warrants	155	$ 1	154
Exercise of warrants (in shares)		76,000
Restricted stock unit vesting	0	$ 0	0
Restricted stock unit vesting (in shares)		6,000
Stock-based compensation	421		421
Balance at end of period at Dec. 31, 2017	$ 4,381	$ 158	$ 238,455	$ (5,886)	$ (228,346)
Balance at end of period (in shares) at Dec. 31, 2017	15,803,736	15,803,000