Annual Rate Adjustment Mechanism, Proposed Earnings Test Deadband

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- Definition

Percent Of Gains Shared With Customers

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- Definition

Public Utilities, Requested Average Cost of Debt, Percentage

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- Definition

Public Utilities, Requested Original Cost Rate Base

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- Definition

Public Utilities Requested Post Test Year Plant Period

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- Definition

Public Utilities, Requested Return On Rate Base, Percentage

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- 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.

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- Definition

Percentage of public utility's requested debt to capital, including debt and equity.

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- Definition

Percentage of public utility's requested equity to capital, including debt and equity.

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- Definition

Amount of public utility's requested rate increase (decrease) with regulatory agency.

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- Definition

Percentage of public utility's requested return on equity.

+ References

No definition available.

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REGULATORY MATTERS (2025 Rate Case) (Details) - USD ($) $ in Millions			9 Months Ended
	Oct. 20, 2026	Oct. 19, 2026	Sep. 30, 2026
Public Utilities, General Disclosures [Line Items]
Percent of long-term trading contract gains shared with customers (percentage)			10.00%
Arizona Corporation Commission \| Subsequent Event
Public Utilities, General Disclosures [Line Items]
Original cost rate base (percentage)	7.25%
Original cost rate base	$ 4,300
Return on equity (percentage)	9.65%
Average original cost of debt (percentage)	4.28%
Capital structure equity percentage	55.00%
Capital structure debt percentage	45.00%
Proposed earnings test deadband	0.50%
Public utilities approved post test year plant additions	6 months
Percent of long-term trading contract gains shared with customers (percentage)	50.00%	10.00%
Arizona Corporation Commission \| Retail Revenues \| Subsequent Event
Public Utilities, General Disclosures [Line Items]
Non-fuel base rate increase (decrease)	$ 114
Arizona Corporation Commission \| Non-Fuel Retail Revenues \| Subsequent Event
Public Utilities, General Disclosures [Line Items]
Non-fuel base rate increase (decrease)	160
Arizona Corporation Commission \| Fuel-Related Retail Revenues \| Subsequent Event
Public Utilities, General Disclosures [Line Items]
Non-fuel base rate increase (decrease)	(26)
Arizona Corporation Commission \| Revenue from Contract with Customer \| Subsequent Event
Public Utilities, General Disclosures [Line Items]
Non-fuel base rate increase (decrease)	(18)
Arizona Corporation Commission \| Reduction in Service Fees \| Subsequent Event
Public Utilities, General Disclosures [Line Items]
Non-fuel base rate increase (decrease)	$ (2)