ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ (30,258)	[1]
Other comprehensive income before reclassifications	92
Amounts reclassified from AOCL	(91)	[2]
Other Comprehensive Income - Net of Tax	1	[3]	110	[3]
Ending balance	(30,257)	[1]
Combined statutory tax rate	40.00%		41.00%
Postretirement Liability Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(27,663)	[1]
Other comprehensive income before reclassifications	0
Amounts reclassified from AOCL	0	[2]
Other Comprehensive Income - Net of Tax	0
Ending balance	(27,663)	[1]
Unrealized Gain (Loss) on Derivatives-Other
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2,450)	[1]
Other comprehensive income before reclassifications	0
Amounts reclassified from AOCL	8	[2]
Other Comprehensive Income - Net of Tax	8
Ending balance	(2,442)	[1]
Unrealized Gain (Loss) on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(75)	[1]
Other comprehensive income before reclassifications	92
Amounts reclassified from AOCL	(4)	[2]
Other Comprehensive Income - Net of Tax	88
Ending balance	13	[1]
Other Comprehensive Income (Loss) of Affiliated Companies
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(70)	[1]
Other comprehensive income before reclassifications	0
Amounts reclassified from AOCL	(95)	[2]
Other Comprehensive Income - Net of Tax	(95)
Ending balance	$ (165)	[1]

[1] For 2015, determined using a combined average statutory tax rate of 40%. For 2014, determined using a combined statutory tax rate of 41%.

[2] See table below.

[3] .