|**Earnings Per Share (Tables)**                                     | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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|**Earnings Per Share [Abstract]**                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Schedule of earnings per weighted average common share outstanding  | The following table presents the calculation of Pinnacle West’s basic and diluted earnings per share (in thousands, except per share amounts):202120202019Net income attributable to common shareholders$618,720$550,559$538,320Weighted average common shares outstanding — basic112,910112,666112,443Net effect of dilutive securities:Contingently issuable performance shares and restricted stock units282276315Weighted average common shares outstanding — diluted113,192112,942112,758Earnings per weighted-average common share outstandingNet income attributable to common shareholders — basic$5.48$4.89$4.79Net income attributable to common shareholders — diluted$5.47$4.87$4.77
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|                                                                    | 2021                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
|Net income attributable to common shareholders                      | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Weighted average common shares outstanding — basic                  | 112,910                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Net effect of dilutive securities:                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Contingently issuable performance shares and restricted stock units | 282                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
|Weighted average common shares outstanding — diluted                | 113,192                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Earnings per weighted-average common share outstanding              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Net income attributable to common shareholders — basic              | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Net income attributable to common shareholders — diluted            | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               

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duration X- DefinitionTabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations.
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