Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	$ 5,752,793	$ 5,553,188
Ending balance	6,021,460	5,752,793
Pension and Other Postretirement Benefits
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(60,725)	(56,522)
OCI (loss) before reclassifications	2,439	(8,370)
Amounts reclassified from accumulated other comprehensive loss	4,401	4,167
Ending balance	(53,885)	(60,725)
Derivative Instruments
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(2,071)	(574)
OCI (loss) before reclassifications	1,077	(2,089)
Amounts reclassified from accumulated other comprehensive loss	18	592
Ending balance	(976)	(2,071)
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(62,796)	(57,096)
OCI (loss) before reclassifications	3,516	(10,459)
Amounts reclassified from accumulated other comprehensive loss	4,419	4,759
Ending balance	(54,861)	(62,796)
Arizona Public Service Company
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	6,345,185	5,998,803
Ending balance	6,750,473	6,345,185
Arizona Public Service Company | Pension and Other Postretirement Benefits
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(40,918)	(34,948)
OCI (loss) before reclassifications	2,043	(9,568)
Amounts reclassified from accumulated other comprehensive loss	3,995	3,598
Ending balance	(34,880)	(40,918)
Arizona Public Service Company | Derivative Instruments
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	0	(574)
OCI (loss) before reclassifications	(18)	(18)
Amounts reclassified from accumulated other comprehensive loss	18	592
Ending balance	0	0
Arizona Public Service Company | Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(40,918)	(35,522)
OCI (loss) before reclassifications	2,025	(9,586)
Amounts reclassified from accumulated other comprehensive loss	4,013	4,190
Ending balance	$ (34,880)	$ (40,918)