Supplementary Cash Flow Information - (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Supplemental Cash Flow Elements [Abstract]
Cash paid for interest	$ 256	$ 694
Cash paid for income taxes	56	43
Class of Stock [Line Items]
Issuance of common stock to placement agent in connection with equity offering (Note 12)	0	5
Issuance of warrants to placement agent in connection with equity offering (Note 12)	0	857
Accounts Payable settled with common stock	0	184
Kanis Agreement
Class of Stock [Line Items]
Notes payable settled with common stock	0	7,900
Note Purchase Agreement With Haldor Topsøe
Class of Stock [Line Items]
Notes payable settled with common stock	0	1,250
Bell Director Note
Class of Stock [Line Items]
Notes payable settled with common stock	$ 0	$ 515