ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		$ (12,851)		$ (12,862)
Other comprehensive loss before reclassifications		73		136
Amounts reclassified from AOCL		(63)		(115)
Other Comprehensive Income (Loss) - Net of Tax	[1]	10	$ (30)	21	$ 26
Ending balance		$ (12,841)		$ (12,841)
Combined statutory tax rate		40.00%	40.00%	40.00%	40.00%
Postretirement Liability Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		$ (12,220)		$ (12,220)
Other comprehensive loss before reclassifications		0		0
Amounts reclassified from AOCL		0		0
Other Comprehensive Income (Loss) - Net of Tax		0		0
Ending balance		(12,220)		(12,220)
Unrealized Gain (Loss) on Derivatives-Other
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(537)		(544)
Other comprehensive loss before reclassifications		0		0
Amounts reclassified from AOCL		7		14
Other Comprehensive Income (Loss) - Net of Tax		7		14
Ending balance		(530)		(530)
Unrealized Gain (Loss) on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(94)		(98)
Other comprehensive loss before reclassifications		73		136
Amounts reclassified from AOCL		(70)		(129)
Other Comprehensive Income (Loss) - Net of Tax		3		7
Ending balance		$ (91)		$ (91)

[1] Determined using a combined average statutory tax rate of 40%.