OTHER ASSETS (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Security deposits	$ 4,063	$ 5,304
Restricted cash	5,728	3,837	$ 4,200	$ 4,127
Other	3,906	1,054
Total	$ 13,697	$ 10,195