Regulatory Matters - Deferred Fuel and Purchased Power Regulatory Asset (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Change in regulatory asset
Deferred fuel and purchased power costs — current period	$ 256,871	$ 93,651	$ 82,481
Amounts refunded/(charged) to customers	(44,557)	12,047	(49,508)
Arizona Public Service Company
Change in regulatory asset
Deferred fuel and purchased power costs — current period	256,871	93,651	82,481
Amounts refunded/(charged) to customers	(44,557)	12,047	(49,508)
ACC | Arizona Public Service Company | Power Supply Adjustor (PSA)
Change in regulatory asset
Beginning balance	175,835	70,137
Deferred fuel and purchased power costs — current period	256,871	93,651
Amounts refunded/(charged) to customers	(44,558)	12,047
Ending balance	$ 388,148	$ 175,835	$ 70,137