Dispositions - Narrative (Details)		3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 01, 2023 USD ($) solarProject project	Sep. 30, 2023 USD ($) MWh project	Sep. 30, 2023 USD ($) MWh project	Dec. 31, 2022 USD ($)	Oct. 01, 2022 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of subsidiary	$ 866,000,000
Gain on sale of subsidiary, after tax	$ 784,000,000
Period to obtain consent (in years)		2 years	2 years
Number of solar projects	2	2	2
Unbilled Contracts Receivable		$ 4,000,000	$ 4,000,000	$ 80,000,000		$ 57,000,000	$ 35,000,000
Clean Energy Businesses | RWE
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Estimate of possible loss (up to)		24,000,000	24,000,000
Unbilled Contracts Receivable		4,000,000	4,000,000
Clean Energy Businesses | RWE | Maximum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Estimate of possible loss (up to)		172,000,000	172,000,000
Disposal Group, Held-for-sale, Not Discontinued Operations | Clean Energy Businesses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration from sale of business	$ 3,993,000,000				$ 6,800,000,000
Gain on sale of subsidiary		$ 0	866,000,000
Gain on sale of subsidiary, after tax			$ 784,000,000
Tax equity projects | project	2	3	3
Transaction costs, before tax		$ 11,000,000	$ 11,000,000	48,000,000
Transaction costs, after tax		8,000,000	8,000,000	$ 35,000,000
Depreciation and amortization, before tax			41,000,000
Depreciation and amortization, after tax			$ 28,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Crane Project
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Holding period (in years)			5 years
Carrying value of tax equity interest		$ 13,000,000	$ 13,000,000
Electric Energy (MWh)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Notional amount | MWh		30,376,045	30,376,045
Broken Bow II | Electric Energy (MWh) | Clean Energy Businesses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Deferred projects | project	1	1	1
Notional amount | MWh		75	75