Intangible Assets and Goodwill - Narrative (Details) - USD ($)	Mar. 12, 2025	Jun. 22, 2022	Apr. 13, 2016	Sep. 30, 2025
Finite-Lived Intangible Assets [Line Items]
Goodwill			$ 1,490,000,000
Storm Recovery Property
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 415,900,000
Energy Transition Property
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 301,900,000
Power supply agreements
Finite-Lived Intangible Assets [Line Items]
Intangible assets, residual value				$ 0
Power supply agreements | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life				19 years