Summary of Significant Accounting Policies - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Utility Plant and Depreciation [Line Items]
Net	$ 18,358,275	$ 16,833,524
Construction work in progress	1,649,542	1,592,659
Intangible assets, net of accumulated amortization	575,978	591,310
Nuclear fuel, net of accumulated amortization	104,274	97,850
Total property, plant and equipment	20,720,104	19,197,899
Electric Service
Utility Plant and Depreciation [Line Items]
Generation	9,687,466	9,675,576
Transmission	4,451,936	4,135,970
Distribution	9,626,629	9,016,843
Energy storage	515,935	276,954
Solar plant	1,501,301	1,159,385
General plant	1,587,029	1,596,222
Plant in service and held for future use	27,370,296	25,860,950
Accumulated depreciation and amortization	(9,012,021)	(9,027,426)
Net	18,358,275	16,833,524
Construction work in progress	1,649,542	1,592,659
Intangible assets, net of accumulated amortization	575,978	591,310
Nuclear fuel, net of accumulated amortization	104,274	97,850
Total property, plant and equipment	20,720,104	19,197,899
Electric Service | Variable Interest Entity
Utility Plant and Depreciation [Line Items]
Total property, plant and equipment	$ 32,035	$ 82,556