Revenue - Schedule of Disaggregation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Total Operating Revenues	$ 4,695,991	$ 4,324,385	$ 3,803,835
Retail Electric Service | Residential
Disaggregation of Revenue [Line Items]
Total Operating Revenues	2,289,196	2,046,111	1,913,324
Retail Electric Service | Non-Residential
Disaggregation of Revenue [Line Items]
Total Operating Revenues	2,048,416	1,767,616	1,586,940
Wholesale Energy Sales
Disaggregation of Revenue [Line Items]
Total Operating Revenues	208,985	383,126	187,640
Transmission Services for Others
Disaggregation of Revenue [Line Items]
Total Operating Revenues	138,631	116,628	99,285
Other Sources
Disaggregation of Revenue [Line Items]
Total Operating Revenues	$ 10,763	$ 10,904	$ 16,646