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.