COMMITMENTS, CONTINGENCIES, AND ENVIRONMENTAL MATTERS (Commitments) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014
Unrecorded Unconditional Purchase Obligation [Line Items]
2014	$ 0
2015	16
2016	0
2017	0
2018	0
Thereafter	0
Total	16
Fuel [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
2014	0
2015	1
2016	0
2017	0
2018	0
Thereafter	0
Total	1
Purchased Power [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
2014	0
2015	15
2016	0
2017	0
2018	0
Thereafter	0
Total	15
TUCSON ELECTRIC POWER COMPANY \| Purchased Power [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
2014	0
2015	7
2016	0
2017	0
2018	0
Thereafter	0
Total	$ 7

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the fifth fiscal year following the latest fiscal year.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 440

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6394976&loc=d3e25336-109308

+ Details

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the next fiscal year following the latest fiscal year.

+ References

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the four fiscal year following the latest fiscal year.

+ References

+ Details

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the second fiscal year following the latest fiscal year.

+ References

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the third fiscal year following the latest fiscal year.

+ References

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Period Type:	instant

- Definition

Amount of the unrecorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

+ References

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing after the fifth fiscal year following the latest fiscal year.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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