Regulatory Matters - Schedule of Changes in The Deferred Fuel and Purchased Power Regulatory Asset (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Change in regulatory asset
Deferred fuel and purchased power costs	$ 324,482	$ 250,288	$ 549,877
Amounts charged to customers	(463,011)	(425,886)	(547,243)
APS
Change in regulatory asset
Deferred fuel and purchased power costs	324,482	250,288	549,877
Amounts charged to customers	(463,011)	(425,886)	(547,243)
Power Supply Adjustor (PSA) | ACC | APS
Change in regulatory asset
Balance at beginning of period	287,597	463,195
Deferred fuel and purchased power costs	324,482	250,288
Amounts charged to customers	(463,011)	(425,886)
Balance at end of period	$ 149,068	$ 287,597	$ 463,195