Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Common Stock	Deficit	Accumulated other comprehensive income	Total shareholders' equity	Non-controlling interests
Net Income (Loss) Attributable to Parent	$ (10,829)		$ (10,822)		$ (10,822)	$ (7)
Beginning balance ( in shares) at Dec. 31, 2017		74,366,824
Beginning balance at Dec. 31, 2017	129,742	$ 430,383	(306,813)	$ 2,289	125,859	3,883
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss	(687)			(687)	(687)
Shares issued for cash by at-the-market offering (in shares)		711,253
Shares issued for cash by at-the-market offering	1,176	$ 1,176			1,176
Share issuance cost	(29)	(29)			(29)
Share-based compensation	1,202	$ 1,202			1,202
Shares issued for the vesting of restricted stock units (in shares)		899,192
Cash paid to fund employee income tax withholding due upon vesting of restricted stock units	(914)	$ (914)			(914)
Ending balance (in shares) at Mar. 31, 2018		75,977,269
Ending balance at Mar. 31, 2018	119,661	$ 431,818	(317,635)	1,602	115,785	3,876
Net Income (Loss) Attributable to Parent	(3,685)
Beginning balance ( in shares) at Dec. 31, 2017		74,366,824
Beginning balance at Dec. 31, 2017	129,742	$ 430,383	(306,813)	2,289	125,859	3,883
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss	(618)
Ending balance (in shares) at Jun. 30, 2018		86,646,509
Ending balance at Jun. 30, 2018	148,611	$ 453,555	(310,486)	1,671	144,740	3,871
Net Income (Loss) Attributable to Parent	7,144		7,149		7,149	(5)
Beginning balance ( in shares) at Mar. 31, 2018		75,977,269
Beginning balance at Mar. 31, 2018	119,661	$ 431,818	(317,635)	1,602	115,785	3,876
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss	69			69	69
Shares issued for cash by at-the-market offering (in shares)		10,504,702
Shares issued for cash by at-the-market offering	21,442	$ 21,442			21,442
Share issuance cost	(536)	(536)			(536)
Share-based compensation	520	$ 520			520
Shares issued for the vesting of restricted stock units (in shares)		0
Shares issued for consulting services (in shares)		164,538
Shares issued for consulting services	311	$ 311			311
Cash paid to fund employee income tax withholding due upon vesting of restricted stock units	0	$ 0			0
Ending balance (in shares) at Jun. 30, 2018		86,646,509
Ending balance at Jun. 30, 2018	148,611	$ 453,555	(310,486)	1,671	144,740	3,871
Net Income (Loss) Attributable to Parent	(12,134)		(12,127)		(12,127)	(7)
Beginning balance ( in shares) at Dec. 31, 2018		91,445,066
Beginning balance at Dec. 31, 2018	144,854	$ 469,303	(332,058)	3,843	141,088	3,766
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss	(136)			(136)	(136)
Shares issued for cash by at-the-market offering (in shares)		754,712
Shares issued for cash by at-the-market offering	2,471	$ 2,471			2,471
Share issuance cost	(62)	(62)			(62)
Share-based compensation	1,121	$ 1,121			1,121
Shares issued for exercise of stock options (in shares)		33,906
Shares issued for exercise of stock options	102	$ 102			102
Shares issued for the vesting of restricted stock units (in shares)		850,150
Shares issued for consulting services (in shares)		18,848
Shares issued for consulting services	52	$ 52			52
Ending balance (in shares) at Mar. 31, 2019		93,102,682
Ending balance at Mar. 31, 2019	136,268	$ 472,987	(344,185)	3,707	132,509	3,759
Net Income (Loss) Attributable to Parent	(21,448)
Beginning balance ( in shares) at Dec. 31, 2018		91,445,066
Beginning balance at Dec. 31, 2018	144,854	$ 469,303	(332,058)	3,843	141,088	3,766
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss	(907)
Ending balance (in shares) at Jun. 30, 2019		95,551,357
Ending balance at Jun. 30, 2019	134,295	$ 481,053	(353,497)	2,936	130,492	3,803
Net Income (Loss) Attributable to Parent	(9,314)		(9,312)		(9,312)	(2)
Beginning balance ( in shares) at Mar. 31, 2019		93,102,682
Beginning balance at Mar. 31, 2019	136,268	$ 472,987	(344,185)	3,707	132,509	3,759
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss	(771)			(771)	(771)
Shares issued for cash by at-the-market offering (in shares)		2,141,817
Shares issued for cash by at-the-market offering	6,595	$ 6,595			6,595
Shares issued for to settle liabilities (in shares)		266,272
Shares issued for to settle liabilities	847	$ 847			847
Share issuance cost	(151)	(151)			(151)
Share-based compensation	663	$ 663			663
Shares issued for exercise of stock options (in shares)		20,899
Shares issued for exercise of stock options	44	$ 44			44
Shares issued for exercise of warrants (in shares)		1,450
Shares issued for exercise of warrants	5	$ 5			5
Shares issued for consulting services (in shares)		18,237
Shares issued for consulting services	63	$ 63			63
Shares issued for consulting services (in shares)		0
Shares issued for consulting services	0				0
Contributions attributable to non-controlling interest	46					46
Ending balance (in shares) at Jun. 30, 2019		95,551,357
Ending balance at Jun. 30, 2019	$ 134,295	$ 481,053	$ (353,497)	$ 2,936	$ 130,492	$ 3,803