Revenue - Schedule of Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 1,308,994	$ 1,121,703	$ 2,260,706	$ 2,066,658
Wholesale Energy Sales
Disaggregation of Revenue [Line Items]
Total operating revenues	10,261	27,282	37,125	122,885
Transmission Services for Others
Disaggregation of Revenue [Line Items]
Total operating revenues	27,541	33,152	55,253	64,943
Other Sources
Disaggregation of Revenue [Line Items]
Total operating revenues	3,163	2,242	6,124	3,942
Residential | Retail Electric Service
Disaggregation of Revenue [Line Items]
Total operating revenues	658,158	542,315	1,090,850	952,039
Non-Residential | Retail Electric Service
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 609,871	$ 516,712	$ 1,071,354	$ 922,849