Approved Recovery of Spending Budget

No definition available.

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- Definition

Year over year cap on Increase in Lost Fixed Cost Recovery rate.

+ References

No definition available.

+ Details

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- Definition

Distributed Generation Requirement Percent of Target Percentage

+ References

No definition available.

+ Details

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- Definition

Energy Efficiency Performance Incentive

+ References

No definition available.

+ Details

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- Definition

Mine Fire Cost Deferral

+ References

No definition available.

+ Details

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- Definition

Over-Recovered Costs for Purchased Power and Fuel

+ References

No definition available.

+ Details

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- Definition

Percentage of Cumulative Annual Retail Kilowatt Savings, Actual

+ References

No definition available.

+ Details

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- Definition

Percentage of Cumulative Annual Retail Kilowatt Savings, Target

+ References

No definition available.

+ Details

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- Definition

Proposed Carryover of Unused Funds

+ References

No definition available.

+ Details

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- Definition

Proposed Recovery of Spending Budget

+ References

No definition available.

+ Details

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- Definition

Proposed Spending Budget

+ References

No definition available.

+ Details

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- Definition

Purchased power and fuel adjustment clause rate.

+ References

No definition available.

+ Details

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- Definition

Renewable Energy Target, Percentage

+ References

No definition available.

+ Details

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- Definition

Purchased power and fuel adjustment clause.

+ References

No definition available.

+ Details

Name:	tep_UnderRecoveredCostsforPurchasedPowerAndFuel
Namespace Prefix:	tep_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Unreimbursed Fuel Costs

+ References

No definition available.

+ Details

Name:	tep_UnreimbursedFuelCosts
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount recovered from insurance. These recoveries reduce costs and losses that are reported as a separate line item under operating expenses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

The amount of regulated power revenues recognized during the period.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Details

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Namespace Prefix:
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- Details

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- Details

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- Details

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Namespace Prefix:
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- Details

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- Details

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- Details

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- Details

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Namespace Prefix:
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- Details

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- Details

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- Details

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REGULATORY MATTERS (Cost Recovery Mechanisms) (Details) $ in Millions	1 Months Ended		12 Months Ended
	Feb. 29, 2016 USD ($)	Jul. 31, 2015 USD ($)	Dec. 31, 2025	Dec. 31, 2020	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) $ / MWh	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Public Utilities, General Disclosures [Line Items]
Renewable Energy Target Percentage						15.00%
Distributed Generation Requirement Target Percentage						30.00%
Purchased Power and Fuel Adjustment Clause [Member]
Public Utilities, General Disclosures [Line Items]
Over-Recovered Costs for Purchased Power and Fuel						$ 18
Under-Recovered Costs for Purchased Power and Fuel							$ 19
2013 TEP Rate Order [Member] \| San Juan [Member] \| Fire [Member]
Public Utilities, General Disclosures [Line Items]
Mine Fire Cost Deferral							10
Insurance Proceeds Received to Date						1	8
Unreimbursed Fuel Costs						$ 1
Renewable Energy Program [Member]
Public Utilities, General Disclosures [Line Items]
Renewable Energy Target Percentage						5.00%
Renewable Energy Budget Spending		$ 57
Renewable Energy Unused Fund Carryover		9
Approved Renewable Energy Budget		$ 48
Renewable Energy Program [Member] \| Scenario, Forecast [Member]
Public Utilities, General Disclosures [Line Items]
Renewable Energy Target Percentage			15.00%		6.00%
Distributed Generation Requirement Target Percentage			30.00%
Recovery Revenue					$ 9
Energy Efficiency Standards [Member]
Public Utilities, General Disclosures [Line Items]
Percentage of Cumulative Annual Retail Kilowatt Savings, Actual						9.30%
Energy Efficiency Standards [Member] \| Scenario, Forecast [Member]
Public Utilities, General Disclosures [Line Items]
Percentage of Electric Energy Efficiency Standards Target Retail Savings on Sales				22.00%
Demand Side Management - Energy Efficiency Standards [Member]
Public Utilities, General Disclosures [Line Items]
Energy Efficiency Performance Incentive						$ 3	2	$ 1
Lost Fixed Cost Recovery Mechanism - Energy Efficiency Standards [Member]
Public Utilities, General Disclosures [Line Items]
Recovery Revenue						$ 12	$ 11	$ 2
Cap on Increase in Lost Fixed Cost Recovery Rate						1.00%
Effective April 2015 Through March 2016 [Member] \| Purchased Power and Fuel Adjustment Clause [Member]
Public Utilities, General Disclosures [Line Items]
Purchased Power And Fuel Adjustment Clause Rate [cents per kwh] \| $ / MWh						0.0068
Effective October 2014 through March 2015 [Member] \| Purchased Power and Fuel Adjustment Clause [Member]
Public Utilities, General Disclosures [Line Items]
Purchased Power And Fuel Adjustment Clause Rate [cents per kwh] \| $ / MWh						0.0050
Effective May 2014 through September 2014 [Member] \| Purchased Power and Fuel Adjustment Clause [Member]
Public Utilities, General Disclosures [Line Items]
Purchased Power And Fuel Adjustment Clause Rate [cents per kwh] \| $ / MWh						0.0010
Effective July 2013 through April 2014 [Member] \| Purchased Power and Fuel Adjustment Clause [Member]
Public Utilities, General Disclosures [Line Items]
Purchased Power And Fuel Adjustment Clause Rate [cents per kwh] \| $ / MWh						(0.0014)
January 2013 through June 2013 [Member] \| Purchased Power and Fuel Adjustment Clause [Member]
Public Utilities, General Disclosures [Line Items]
Purchased Power And Fuel Adjustment Clause Rate [cents per kwh] \| $ / MWh						0.0077
Subsequent Event [Member] \| Energy Efficiency Standards [Member]
Public Utilities, General Disclosures [Line Items]
Approved Recovery of Spending Budget	$ 14