PREPAID EXPENSES AND OTHER CURRENT ASSETS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
PREPAID EXPENSES AND OTHER CURRENT ASSETS
Prepaid regulatory fees	$ 1,434	$ 512
Prepaid development costs	526	485
Prepaid insurance	310	328
Other current assets	456	304
Other prepaid expenses	279	276
Prepaid expenses and other current assets	$ 3,005	$ 1,905