v3.26.1
REGULATORY MATTERS (2025 Rate Case) (Details) - Arizona Corporation Commission - Subsequent Event
$ in Millions
Apr. 13, 2026
USD ($)
Public Utilities, General Disclosures [Line Items]  
Original cost rate base (percentage) 7.73%
Original cost rate base $ 4,300
Return on equity (percentage) 10.50%
Average original cost of debt (percentage) 4.28%
Capital structure equity percentage 55.00%
Capital structure debt percentage 45.00%
Proposed earnings test deadband 0.20%
Retail Revenues  
Public Utilities, General Disclosures [Line Items]  
Non-fuel base rate increase (decrease) $ 159
Non-Fuel Retail Revenues  
Public Utilities, General Disclosures [Line Items]  
Non-fuel base rate increase (decrease) 205
Fuel-Related Retail Revenues  
Public Utilities, General Disclosures [Line Items]  
Non-fuel base rate increase (decrease) (26)
Revenue from Contract with Customer  
Public Utilities, General Disclosures [Line Items]  
Non-fuel base rate increase (decrease) $ (20)