Note 2 - Prepaid Expenses and Other Current Assets - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Rio Grande LNG site option	$ 73	$ 508
Short-term security deposits	49	18
Prepaid insurance	371	233
Prepaid marketing and sponsorships	65	242
Prepaid rent	79	10
Prepaid subscriptions	137	26
Equity issuance costs	198
Other	316	273
Total prepaid expenses and other current assets	$ 1,288	$ 1,310