Capital Lease Fair Value Purchase Price

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- Definition

Capital Lease Obligation, Term

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- Definition

Commitment to Purchase Capital Lease Interests

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- Definition

Fixed price to acquire leased interest in facilities.

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- Definition

Generating Capacity Purchased, in MWs

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- Definition

Gila Unit 2 [Abstract]

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- Definition

Increase in Capital Lease Obligation due to Purchase Commitment

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- Definition

Jointly Owned, Percentage of Interest Committed to Purchase

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- Definition

Jointly Owned, Percentage of Interest Purchased

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- Definition

Long-term Contract for Purchase of Electric Power, Estimated Monthly Charge

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- Definition

Number of Leases

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- Definition

Percentage of ownership in generating units.

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- Definition

Springerville [Abstract]

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- Definition

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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- Definition

Amount of capital lease obligation due within one year or the normal operating cycle, if longer.

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- Definition

The percentage points added to the reference rate to compute the variable rate on the interest rate derivative.

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Fixed interest rate related to the interest rate derivative.

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- Definition

Nominal or face amount used to calculate payments on the derivative liability.

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The proportionate share of interest (percent) in a jointly owned utility plant.

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Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Nominal or face amount used to calculate payments on a nonderivative instrument.

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- Definition

The cash outflow for payments to acquire rented equipment which is recorded as an asset.

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DEBT, CREDIT FACILITY, AND CAPITAL LEASE OBLIGATIONS (Capital Lease Narrative) (Details) $ in Thousands	1 Months Ended		12 Months Ended
	May 30, 2018 USD ($)	Sep. 30, 2016 USD ($) MW	Dec. 31, 2018 USD ($) lease MW	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2019 USD ($)
Gila Unit 2 [Abstract]
Total Capital Lease Obligations			$ 193,000	$ 39,000
Current portion of capital lease			172,510	10,749
Non-current portion of capital lease			$ 19,773	28,519
Springerville [Abstract]
Generating capacity purchased, in MWs \| MW			190
Fixed purchase price			$ 0	$ 0	$ 36,000
Interest Rate Swap
Springerville [Abstract]
Notional amount			$ 12,000
Springerville Common Facilities Lease Debt \| Interest Rate Swap
Springerville [Abstract]
Fixed rate of interest related to interest rate swap (in percentage)			5.77%
Notional amount			$ 12,000
Notional amount of debt			$ 2,000
Derivative basis spread (in percentage)			2.00%	1.88%
Gila River Unit 2
Gila Unit 2 [Abstract]
Total Capital Lease Obligations			$ 164,000	$ 0
Springerville Unit One \| Completion of Purchase of Equity Interest
Springerville [Abstract]
Fixed price to acquire leased interest in facilities		$ 85,000
Percentage of ownership in generating units (in percentage)		100.00%
Generating capacity purchased, in MWs \| MW		387
Springerville Common Facilities
Gila Unit 2 [Abstract]
Total Capital Lease Obligations			$ 29,000	$ 39,000
Springerville [Abstract]
Number of operating lease \| lease			2
Fixed purchase price			$ 68,000
Lessee, operating lease, renewal term (in years)			2 years
Percentage of interest committed to purchase (in percentage)			14.00%
Percentage of interest purchased (in percentage)				17.80%
Payments to acquire Springerville common facilities				$ 38,000
Percentage of ownership in generating station (in percentage)				67.80%
Increase (decrease) in capital lease obligation				$ (36,000)
Salt River Project Agricultural Improvement and Power District
Gila Unit 2 [Abstract]
Capital lease obligation, term (in months)	20 months
Long-term contract for purchase of electric power, estimated monthly charge	$ 1,000
Scenario, Forecast \| Salt River Project Agricultural Improvement and Power District
Gila Unit 2 [Abstract]
Capital lease fair value purchase price						$ 164,000