v3.19.1
CASH, CASH EQUIVALENTS, AND INVESTMENTS (Details) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Cash and Cash Equivalents [Abstract]        
Cash and cash equivalents $ 33,222 $ 1,068 $ 4,464  
Restricted cash included in Other current assets 0 0 525  
Restricted cash included in Other current, net 482 481 3,481  
Total cash, cash equivalents, and restricted cash shown in the statement of cash flows $ 33,704 $ 1,549 $ 8,470 $ 9,784