Revenue - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Total Operating Revenues	$ 5,339,939	$ 5,124,915	$ 4,695,991
Wholesale Energy Sales
Disaggregation of Revenue [Line Items]
Total Operating Revenues	108,661	96,857	208,985
Transmission Services for Others
Disaggregation of Revenue [Line Items]
Total Operating Revenues	129,667	119,038	138,631
Other Sources
Disaggregation of Revenue [Line Items]
Total Operating Revenues	17,355	11,273	10,763
Residential | Retail Electric Service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	2,541,320	2,562,822	2,289,196
Non-Residential | Retail Electric Service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	$ 2,542,936	$ 2,334,925	$ 2,048,416