Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Prepaid Expenses and Other Current Assets
Rio Grande LNG site option	$ 57	$ 495
Short-term security deposits	364	349
Shoal Point Leases	75
Prepaid insurance	281	21
Other	266	231
Total prepaid expenses and other current assets	$ 1,043	$ 1,096