Revenue - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Disaggregation of Revenue [Line Items]
Total Operating Revenues	$ 1,149,597	$ 1,032,280
Wholesale Energy Sales
Disaggregation of Revenue [Line Items]
Total Operating Revenues	14,976	24,824
Transmission Services for Others
Disaggregation of Revenue [Line Items]
Total Operating Revenues	32,027	25,547
Other Sources
Disaggregation of Revenue [Line Items]
Total Operating Revenues	7,160	8,129
Residential | Retail Electric Service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	493,701	448,923
Non-Residential | Retail Electric Service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	$ 601,733	$ 524,857