ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Accumulated Other Comprehensive Loss (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
BALANCE     $ 466,765  
Other comprehensive gain (loss) before reclassification     (224) $ (9)
Actuarial gain (loss)     (358)  
Reclassification to net income (loss) [1]     814 713
TOTAL OTHER COMPREHENSIVE INCOME $ 114 $ 274 232 704
BALANCE 495,817   495,817  
Unrealized gain (loss) on available-for-sale securities [Member]        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
BALANCE     (111) (28)
Other comprehensive gain (loss) before reclassification     (256) (9)
TOTAL OTHER COMPREHENSIVE INCOME     (256) (9)
BALANCE (367) (37) (367) (37)
Actuarial gain (loss) on retirement plan [Member]        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
BALANCE [2]     (9,708) (4,354)
Actuarial gain (loss) [2]     (358)  
Reclassification to net income (loss) [1],[2]     814 713
TOTAL OTHER COMPREHENSIVE INCOME [2]     456 713
BALANCE [2] (9,252) (3,641) (9,252) (3,641)
Change in cumulative foreign currency translation adjustment [Member]        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Other comprehensive gain (loss) before reclassification     32  
TOTAL OTHER COMPREHENSIVE INCOME     32  
BALANCE 32   32  
Accumulated other comprehensive loss [Member]        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
BALANCE     (9,819) (4,382)
TOTAL OTHER COMPREHENSIVE INCOME     232  
BALANCE $ (9,587) $ (3,678) $ (9,587) $ (3,678)
[1] The Company reclassified amortization of prior service cost and actuarial loss for its retirement plan from accumulated other comprehensive loss to net income (loss) of $814,000 and $713,000 for the nine months ended September 30, 2016 and 2015, respectively.
[2] Refer to Note 13: Supplemental Executive Retirement Plan.