PENSION AND OTHER POSTRETIREMENT BENEFITS 3 (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Regulatory Assets, Amortization of Net Prior Service Cost (Credit)	$ 206
Regulatory Assets, Amortization of Net Actuarial Gains (Losses)	5,141
Defined Benefit Plan, Amortization of Net Prior Service Cost (Credit)	44
Defined Benefit Plan, Amortization of Net Actuarial Gains (Losses)	3,599
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Regulatory Assets, Amortization of Net Prior Service Cost (Credit)	(195)
Regulatory Assets, Amortization of Net Actuarial Gains (Losses)	1,605
Defined Benefit Plan, Amortization of Net Prior Service Cost (Credit)	(89)
Defined Benefit Plan, Amortization of Net Actuarial Gains (Losses)	$ 257