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Retirement Plans and Other Postretirement Benefits - Additional Information (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items] |  |  |
Ultimate healthcare cost trend rate (pre-65 participants) | 4.75% | 4.75% |
Initial and ultimate healthcare cost trend rate (post-65 participants) | 2.00% | 2.00% |
Funded percentage (more than) | 100.00% | 100.00% |
Partnership funding commitments, contribution amount (up to) | $ 50,000,000 |  |
Partnership funding commitments, funded amount | $ 38,000,000 |  |
Other Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Expected long-term return on plan assets for next fiscal year (as a percent) | 7.00% |  |
Retiree medical cost reimbursement | $ 23,000,000 | $ 26,000,000 | $ 24,000,000
Pension Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Expected long-term return on plan assets for next fiscal year (as a percent) | 6.90% |  |
Employer contributions |  |  | 100,000,000
Minimum contributions under MAP-21 | $ 0 |  |
Pinnacle West |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Expenses recorded for the defined contribution savings plan | $ 12,000,000 | $ 12,000,000 | $ 12,000,000
Arizona Public Service Company |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
APS's employees share of total cost of the plans (as a percent) | 99.00% |  |

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- Definition An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation during next fiscal year. + References No definition available. + Details
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- Definition Defined Benefit Plan, Post-65 Health Care Cost Trend Rate Assumed for Next Fiscal Year, Used in Calculating Benefit Obligation + References No definition available. + Details
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- Definition Defined Benefit Plans Estimated Minimum Future Employer Contributions, Next Three Fiscal Years + References No definition available. + Details
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