v3.25.1
Debt and Liquidity Matters - Additional Information (Details) - USD ($)
$ in Millions
3 Months Ended
Apr. 29, 2025
Dec. 17, 2024
Dec. 05, 2024
Mar. 31, 2025
Aug. 02, 2024
APS          
Long-Term Debt and Liquidity Matters [Line Items]          
Public utilities, request to permanently modify permitted yearly equity infusions   2.50%      
Public utilities, number of basis point of approved rate       0.0050  
Term Loan | APS          
Long-Term Debt and Liquidity Matters [Line Items]          
Debt instrument term     364 days    
Notes issued     $ 400.0    
Debt instrument, basis spread on variable rate     0.90%    
Term Loan | APS | Subsequent Event          
Long-Term Debt and Liquidity Matters [Line Items]          
Proceeds from issuance of unsecured debt $ 400.0        
Revolving credit facility | Revolving Credit Facility Maturing April 2029 | APS          
Long-Term Debt and Liquidity Matters [Line Items]          
Current borrowing capacity on credit facility       $ 1,250.0  
Accordion feature, increase limit       400.0  
Long-term line of credit       $ 0.0  
Debt, weighted average interest rate       4.64%  
Maximum borrowing capacity on credit facility upon satisfaction of certain conditions and consent of lenders       $ 1,650.0  
Letter of Credit | APS          
Long-Term Debt and Liquidity Matters [Line Items]          
Outstanding letters of credit       18.7  
Letter of Credit | Revolving Credit Facility Maturing April 2029 | APS          
Long-Term Debt and Liquidity Matters [Line Items]          
Outstanding letters of credit       0.0  
Commercial paper | APS          
Long-Term Debt and Liquidity Matters [Line Items]          
Maximum commercial paper support available under credit facility       1,000.0  
Commercial paper | Revolving Credit Facility Maturing April 2029 | APS          
Long-Term Debt and Liquidity Matters [Line Items]          
Commercial paper       $ 627.0  
Pinnacle West | Term Loan          
Long-Term Debt and Liquidity Matters [Line Items]          
Debt instrument term       364 days  
Notes issued       $ 200.0  
Debt instrument, basis spread on variable rate       0.95%  
Pinnacle West | Revolving credit facility | Revolving Credit Facility Maturing April 2029          
Long-Term Debt and Liquidity Matters [Line Items]          
Current borrowing capacity on credit facility       $ 200.0  
Accordion feature, increase limit       300.0  
Long-term line of credit       0.0  
Pinnacle West | Letter of Credit | Revolving Credit Facility Maturing April 2029          
Long-Term Debt and Liquidity Matters [Line Items]          
Outstanding letters of credit       $ 0.0  
Pinnacle West | Commercial paper | Revolving Credit Facility Maturing April 2029          
Long-Term Debt and Liquidity Matters [Line Items]          
Commercial paper         $ 44.0
Debt, weighted average interest rate       4.65%