GOODWILL (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Changes in the carrying amount of goodwill    
Balance at the beginning $ 166,906 $ 164,959
Foreign currency impact (238)  
Accumulated impairment losses (130,268) (130,268)
Balance at the beginning 36,400 34,691
Acquisitions 1,066 1,947
Foreign currency impact (180) (238)
Changes during the period 886 1,709
Balance at the end 167,972 166,906
Foreign currency impact (418) (238)
Accumulated impairment losses (130,268) (130,268)
Balance at the end $ 37,286 $ 36,400