REGULATORY MATTERS (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Regulatory Assets:
Regulatory assets, current	$ 8,650us-gaap_RegulatoryAssetsCurrent	$ 10,752us-gaap_RegulatoryAssetsCurrent
Regulatory assets, long-term	204,947us-gaap_RegulatoryAssetsNoncurrent	209,717us-gaap_RegulatoryAssetsNoncurrent
Total Regulatory Assets	213,597us-gaap_RegulatoryAssets	220,469us-gaap_RegulatoryAssets
Regulatory Liabilities:
Regulatory liabilities, current	5,559us-gaap_RegulatoryLiabilityCurrent	7,898us-gaap_RegulatoryLiabilityCurrent
Regulatory liabilities, long-term	133,303us-gaap_RegulatoryLiabilityNoncurrent	128,471us-gaap_RegulatoryLiabilityNoncurrent
Total Regulatory Liabilities	138,862us-gaap_RegulatoryLiabilities	136,369us-gaap_RegulatoryLiabilities
Over recovered fuel costs
Regulatory Liabilities:
Regulatory liabilities, current	2,058	4,227
Regulatory liabilities, long-term	4,096	1
Current portion of long-term regulatory liabilities
Regulatory Liabilities:
Regulatory liabilities, current	3,501	3,671
Regulatory liabilities, long-term	(3,501)	(3,671)
Costs of removal
Regulatory Liabilities:
Regulatory liabilities, long-term	92,259	90,527
SWPA payment for Ozark Beach lost generation
Regulatory Liabilities:
Regulatory liabilities, long-term	16,064	16,744
Income taxes
Regulatory Liabilities:
Regulatory liabilities, long-term	11,406	11,451
Deferred construction accounting costs - fuel
Regulatory Liabilities:
Regulatory liabilities, long-term	7,809	7,849
Unamortized gain on interest rate derivative
Regulatory Liabilities:
Regulatory liabilities, long-term	3,159	3,201
Pension and other postretirement benefits
Regulatory Liabilities:
Regulatory liabilities, long-term	2,011	2,369
Under recovered fuel costs
Regulatory Assets:
Regulatory assets, current	323	2,618
Regulatory assets, long-term		640
Current portion of long-term regulatory assets
Regulatory Assets:
Regulatory assets, current	8,327	8,134
Regulatory assets, long-term	(8,327)	(8,134)
Pension and other postretirement benefits
Regulatory Assets:
Regulatory assets, long-term	108,341	111,121
Income taxes
Regulatory Assets:
Regulatory assets, long-term	47,101	47,177
Deferred construction accounting costs
Regulatory Assets:
Regulatory assets, long-term	15,389	15,521
Unamortized loss on reacquired debt
Regulatory Assets:
Regulatory assets, long-term	10,236	10,405
System reliability - vegetation management
Regulatory Assets:
Regulatory assets, long-term	4,025	5,337
Storm costs
Regulatory Assets:
Regulatory assets, long-term	4,009	4,183
Asset retirement obligation
Regulatory Assets:
Regulatory assets, long-term	5,413	5,145
Customer programs
Regulatory Assets:
Regulatory assets, long-term	5,280	5,253
Unamortized loss on interest rate derivative
Regulatory Assets:
Regulatory assets, long-term	932	943
Deferred operating and maintenance expense
Regulatory Assets:
Regulatory assets, long-term	661	910
Other
Regulatory Assets:
Regulatory assets, long-term	1,732	2,179
Ice storm and tornado cost
Regulatory Assets:
Regulatory assets, long-term	3,200
Electric \| Unsettled derivative losses- electric segment
Regulatory Assets:
Regulatory assets, long-term	$ 10,155	$ 9,037

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- Definition

The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 340

-Section 50

-Paragraph 1

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Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost.

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Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.

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The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 405

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394

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The amount for the individual regulatory current liability as itemized in a table of regulatory current liabilities as of the end of the period.

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The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.24)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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