SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 5) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash and Cash Equivalents
Carrying value of cash and cash equivalents	$ 25,492	$ 8,837	$ 19,587	$ 27,506
Proceeds collected through a surcharge on certain customers' bills	400
Restricted Cash
Carrying value of restricted cash	$ 400	$ 500