Regulatory Matters - Schedule of Changes in The Deferred Fuel and Purchased Power Regulatory Asset (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Change in regulatory asset
Deferred fuel and purchased power costs	$ 244,109	$ 486,382
Amounts charged to customers	(340,030)	(420,277)
APS
Change in regulatory asset
Deferred fuel and purchased power costs	244,109	486,382
Amounts charged to customers	(340,030)	(420,277)
Power Supply Adjustor (PSA) | ACC | APS
Change in regulatory asset
Balance at beginning of period	463,195	460,561
Deferred fuel and purchased power costs	244,109	486,382
Amounts charged to customers	(340,030)	(420,277)
Balance at end of period	$ 367,274	$ 526,666