Revenue - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Disaggregation of Revenue [Line Items]
Operating revenues	$ 1,820,741	$ 1,768,801	$ 4,211,772	$ 4,029,507
Regulatory cost recovery revenue increase (decrease)	(1,000)	13,000	$ (26,000)	28,000
Retail Electric Service
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, payment terms			21 days
Electric and Transmission Service
Disaggregation of Revenue [Line Items]
Operating revenues	$ 1,822,000	$ 1,756,000	$ 4,186,000	$ 4,002,000