Debt and Liquidity Matters - Additional Information (Details) - USD ($) $ in Thousands								1 Months Ended	9 Months Ended
	Sep. 04, 2025	Aug. 15, 2025	May 15, 2025	Apr. 29, 2025	Dec. 23, 2024	Dec. 20, 2024	Dec. 05, 2024	Sep. 30, 2025	Sep. 30, 2025	Sep. 30, 2024	Jun. 30, 2024
Long-Term Debt and Liquidity Matters [Line Items]
Number of shares issued in transaction (in shares)									2,199,415
February 2024 Forward Sale Agreements
Long-Term Debt and Liquidity Matters [Line Items]
Number of shares issued in transaction (in shares)					5,377,115			243,186
Proceeds from issuance of common stock	$ 15,350				$ 345,049			$ 15,000
APS
Long-Term Debt and Liquidity Matters [Line Items]
Equity infusion from Pinnacle West			$ 300,000						$ 300,000	$ 450,000
Public utilities, request to permanently modify permitted yearly equity infusions									2.50%
Public utilities, number of basis point of approved rate								0.0050	0.0050
Term Loan | APS
Long-Term Debt and Liquidity Matters [Line Items]
Debt instrument term		364 days					364 days
Debt instrument, face amount							$ 400,000
Debt instrument, basis spread on variable rate							0.90%
Repayments of unsecured debt		$ 400,000
Proceeds from issuance of unsecured debt				$ 400,000
Term Loan | Senior Notes | APS
Long-Term Debt and Liquidity Matters [Line Items]
Repayments of unsecured debt			$ 300,000
Senior Unsecured Notes Maturing May 2025 | Senior Notes | APS
Long-Term Debt and Liquidity Matters [Line Items]
Interest rate			3.15%
Senior Unsecured Notes Maturing August 2055 | Senior Notes | APS
Long-Term Debt and Liquidity Matters [Line Items]
Debt instrument, face amount		$ 700,000
Interest rate		5.90%
Senior Unsecured Notes Maturing August 2034 | Senior Notes
Long-Term Debt and Liquidity Matters [Line Items]
Interest rate		5.70%
Senior Unsecured Notes Maturing August 2034 | Senior Notes | APS
Long-Term Debt and Liquidity Matters [Line Items]
Debt instrument, increase (decrease), net		$ 250,000
Revolving credit facility | Revolving Credit Facility Maturing April 2029 | APS
Long-Term Debt and Liquidity Matters [Line Items]
Current borrowing capacity on credit facility								$ 1,250,000	$ 1,250,000
Accordion feature, increase limit								400,000	400,000
Long-term line of credit								$ 0	$ 0
Debt, weighted average interest rate								4.26%	4.26%
Maximum borrowing capacity on credit facility upon satisfaction of certain conditions and consent of lenders								$ 1,650,000	$ 1,650,000
Letter of Credit | APS
Long-Term Debt and Liquidity Matters [Line Items]
Outstanding letters of credit								33,200	33,200
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								1,000,000	1,000,000
Commercial paper | Revolving Credit Facility Maturing April 2029 | APS
Long-Term Debt and Liquidity Matters [Line Items]
Commercial paper								421,000	$ 421,000
Pinnacle West | Term Loan
Long-Term Debt and Liquidity Matters [Line Items]
Debt instrument term									364 days
Debt instrument, face amount								200,000	$ 200,000
Debt instrument, basis spread on variable rate									0.95%
Loan amount drawn						$ 200,000
Pinnacle West | Senior Unsecured Notes Maturing May 2028 | Senior Notes
Long-Term Debt and Liquidity Matters [Line Items]
Debt instrument, face amount			$ 400,000
Interest rate			4.90%
Pinnacle West | Senior Unsecured Notes Maturing May 2025 | Senior Notes
Long-Term Debt and Liquidity Matters [Line Items]
Debt instrument, face amount			$ 400,000
Interest rate			5.15%
Pinnacle West | Senior Notes Maturing May 2025 | Senior Notes
Long-Term Debt and Liquidity Matters [Line Items]
Interest rate			1.30%
Repayments of unsecured debt			$ 500,000
Pinnacle West | Convertible Notes Due Maturing June 2027 | Convertible Debt
Long-Term Debt and Liquidity Matters [Line Items]
Debt instrument, face amount											$ 525,000
Interest rate											4.75%
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								200,000	$ 200,000
Accordion feature, increase limit								300,000	300,000
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								$ 55,000	$ 55,000
Debt, weighted average interest rate								4.28%	4.28%