PENSION AND OTHER POSTRETIREMENT BENEFITS 4 (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Amounts Recognized in the Statement of Financial Position Consist of [Abstract]
Current Liabilities	$ (1,272,000)	$ (1,275,000)
Noncurrent Liabilities	(105,168,000)	(109,021,000)
Pension Benefits [Member]
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning of Year	194,990,000	167,500,000
Service Cost	4,533,000	3,918,000	3,426,000
Interest Cost	9,622,000	9,524,000	9,197,000
Actuarial Loss	23,952,000	22,162,000
Retiree Contributions	0	0
Plan Amendments	0	102,000
Benefits Paid	(8,708,000)	(8,216,000)
Benefit Obligation, Ending of Year	224,389,000	194,990,000	167,500,000
Change in Plan Assets [Roll Forward]
Fair Value of Plan Assets at Beginning of Year	116,718,000	120,600,000
Actual Return on Plan Assets	15,935,000	3,114,000
Employer Contributions	26,215,000	1,220,000
Retiree Contributions	0	0
Benefits Paid	(8,708,000)	(8,216,000)
Fair Value of Plan Assets at End of Year	150,160,000	116,718,000	120,600,000
Funded Status at End of Year:	(74,229,000)	(78,272,000)
Amounts Recognized in the Statement of Financial Position Consist of [Abstract]
Current Liabilities	(1,272,000)	(1,275,000)
Noncurrent Liabilities	(72,796,000)	(76,752,000)
Net Amount Recognized at End of Year	(74,068,000)	(78,027,000)
Amounts Recognized in Regulatory Assets Consist of [Abstract]
Prior Service Costs (Credit)	842,000	1,049,000
Net Actuarial Loss	67,871,000	60,762,000
Amount Recognized in Regulatory Assets	68,713,000	61,811,000	47,197,000
Amounts Recognized in Accumulated Other Comprehensive Loss [Abstract]
Prior Service Costs (Credit)	111,000	153,000
Net Actuarial Loss	35,320,000	31,613,000
Amount Recognized in Accumulated Other Comprehensive Loss	35,431,000	31,766,000	23,763,000
Projected benefit obligation	186,400,000	163,100,000
Accumulated benefit obligation	168,900,000	147,300,000
Pension Benefits [Member] | Unconsolidated Affiliate [Member]
Change in Plan Assets [Roll Forward]
Funded Status at End of Year:	161,000	245,000
Pension Benefits [Member] | Parent Company [Member]
Change in Plan Assets [Roll Forward]
Funded Status at End of Year:	(74,068,000)	(78,027,000)
Other Postretirement Benefits [Member]
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning of Year	64,451,000	58,465,000
Service Cost	1,037,000	996,000	920,000
Interest Cost	3,001,000	3,201,000	3,267,000
Actuarial Loss	3,861,000	5,018,000
Retiree Contributions	342,000	370,000
Plan Amendments	0	631,000
Benefits Paid	(3,913,000)	(4,230,000)
Benefit Obligation, Ending of Year	68,779,000	64,451,000	58,465,000
Change in Plan Assets [Roll Forward]
Fair Value of Plan Assets at Beginning of Year	31,896,000	32,119,000
Actual Return on Plan Assets	4,263,000	(373,000)
Employer Contributions	3,444,000	4,010,000
Retiree Contributions	342,000	370,000
Benefits Paid	(3,913,000)	(4,230,000)
Fair Value of Plan Assets at End of Year	36,032,000	31,896,000	32,119,000
Funded Status at End of Year:	(32,747,000)	(32,555,000)
Amounts Recognized in the Statement of Financial Position Consist of [Abstract]
Current Liabilities	0	0
Noncurrent Liabilities	(32,372,000)	(32,269,000)
Net Amount Recognized at End of Year	(32,372,000)	(32,269,000)
Amounts Recognized in Regulatory Assets Consist of [Abstract]
Prior Service Costs (Credit)	758,000	563,000
Net Actuarial Loss	26,426,000	25,872,000
Amount Recognized in Regulatory Assets	27,184,000	26,435,000	21,064,000
Amounts Recognized in Accumulated Other Comprehensive Loss [Abstract]
Prior Service Costs (Credit)	68,000	(14,000)
Net Actuarial Loss	4,127,000	4,759,000
Amount Recognized in Accumulated Other Comprehensive Loss	4,195,000	4,745,000	3,166,000
Other Postretirement Benefits [Member] | Unconsolidated Affiliate [Member]
Change in Plan Assets [Roll Forward]
Funded Status at End of Year:	375,000	286,000
Other Postretirement Benefits [Member] | Parent Company [Member]
Change in Plan Assets [Roll Forward]
Funded Status at End of Year:	(32,372,000)	(32,269,000)
Supplemental Employee Retirement Plans, Defined Benefit [Member]
Amounts Recognized in Accumulated Other Comprehensive Loss [Abstract]
Projected benefit obligation	38,000,000	31,900,000
Accumulated benefit obligation	$ 36,300,000	$ 29,600,000