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Retirement Plans and Other Postretirement Benefits - Additional Information (Details) - USD ($) |  | 12 Months Ended
--- | --- | ---
Jan. 04, 2021 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Initial pre-65 ultimate health care cost trend rate (as a percent) |  | 4.75% | 4.75% | 4.75%
Initial post-65 healthcare cost trend rate (as a percent) |  | 2.00% | 2.00% |
Funded percentage (more than) |  | 100.00% |  |
Partnership funding commitments, contribution amount (up to) |  | $ 50,000,000 |  |
Partnership funding commitments, funded amount |  | 38,000,000 |  |
Pension Benefits |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Transfer to active union medical account | $ (106,000,000) | $ 0 | $ 0 |
Expected long-term return on plan assets for next fiscal year (as a percent) |  | 5.00% |  |
Contributions |  |  |  |
Employer contributions |  | $ 100,000,000 | 100,000,000 | $ 150,000,000
Minimum contributions under MAP-21 |  |  |  |
Minimum contributions under MAP-21 |  | 0 |  |
Other Benefits |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Transfer to active union medical account | 106,000,000 | $ 105,852,000 | 0 |
Expected long-term return on plan assets for next fiscal year (as a percent) |  | 5.50% |  |
Contributions |  |  |  |
Employer contributions |  | $ 0 | 0 |
Minimum contributions under MAP-21 |  |  |  |
Retiree medical cost reimbursement |  | 24,000,000 | 26,000,000 | 30,000,000
Pinnacle West |  |  |  |
Minimum contributions under MAP-21 |  |  |  |
Expenses recorded for the defined contribution savings plan |  | $ 12,000,000 | $ 11,000,000 | $ 11,000,000
Arizona Public Service Company |  |  |  |
Minimum contributions under MAP-21 |  |  |  |
APS's employees share of total cost of the plans (as a percent) |  | 99.00% |  |
Arizona Public Service Company | Other Benefits |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Transfer to active union medical account | $ 106,000,000 |  |  |

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- Definition Defined Benefit Plan, Accumulated Benefit Obligation, Funded Percentage + References No definition available. + Details
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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 Percentage of the subsidiary's share of the total cost of the benefit plans relative to the consolidated entity's total cost. + References No definition available. + Details
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