Acquisitions and Dispositions - Acquisitions (Details) $ / shares in Units, customer in Thousands, $ in Millions				12 Months Ended
	Jan. 30, 2026 USD ($) facility GW state customer shares	Apr. 10, 2025 USD ($) facility MW	Mar. 10, 2023 USD ($) customer $ / shares	Dec. 31, 2025 USD ($) GW	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Business Combination [Line Items]
Proceeds from issuance of long-term debt				$ 6,676	$ 3,200	$ 731
Acquisition-related transaction and integration costs				$ 74	30	119
Generation capacity (in MW) | GW				12
Proceeds from issuance of preferred stock, net of fees				$ 0	0	635
Issuance of Series A Preferred Stock						635
Proceeds from credit facilities				1,575	$ 1,050	3,020
LS Power Portfolio
Business Combination [Line Items]
Acquisition-related transaction and integration costs				32
Texas Generation Portfolio
Business Combination [Line Items]
Number of power generating facilities acquired | facility		6
Total consideration		$ 560
Acquisition-related transaction and integration costs				$ 5
Generation capacity (in MW) | MW		738
Acquisition, working capital adjustments		$ 2
Vivint
Business Combination [Line Items]
Customers | customer			2,000
Total consideration			$ 2,623
Acquisition, share price (in usd per share) | $ / shares			$ 12.00
Acquisition costs						$ 38
Vivint | Senior Secured First Lien Notes, due 2033 | Senior Notes
Business Combination [Line Items]
Proceeds from issuance of long-term debt			$ 724
Aggregate principal amount			$ 740
Interest rate, stated percentage			7.00%
Vivint | Revolving Credit Facility
Business Combination [Line Items]
Proceeds from credit facilities			$ 900
Vivint | Series A Preferred Stock
Business Combination [Line Items]
Proceeds from issuance of preferred stock, net of fees			635
Issuance of Series A Preferred Stock			$ 650
Preferred stock, dividend rate (as percent)			10.25%
Subsequent Event | LS Power Portfolio
Business Combination [Line Items]
Number of gas-fired facilities acquired | facility	18
States where entity is located | state	9
Acquisition, shares issued (in shares) | shares	24,250,000
Cash paid to acquire business excluding working capital adjustments	$ 6,400
Acquisition working capital and other adjustments	479
Proceeds from credit facility	2,500
Acquisition, liabilities assumed	3,200
Total consideration	$ 10,579
Generation capacity (in MW) | GW	13
Subsequent Event | LS Power Portfolio | New Secured Notes
Business Combination [Line Items]
Proceeds from issuance of long-term debt	$ 4,400
Subsequent Event | LS Power Portfolio | Natural Gas
Business Combination [Line Items]
Number of power generating facilities acquired | GW	13
Subsequent Event | LS Power Portfolio | Commercial And industrial Virtual Power Plant Platform
Business Combination [Line Items]
Customers | customer	2