Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Prepaid Expenses and Other Current Assets
Rio Grande LNG site option	$ 508	$ 1,080
Short-term security deposits	18	364
Galveston Bay leases		100
Rio Bravo Pipeline options	54	111
Prepaid insurance	233	208
Prepaid marketing and sponsorships	242	55
Other	255	181
Total prepaid expenses and other current assets	1,310	2,099
Lease option expense relating to Rio Grande LNG site option	$ 572	$ 584