Debt, Credit Facilities and Financings - Schedule of Debt (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Long -term debt before unamortized premiums, discounts and issuance costs	$ 16,130	$ 16,469
Unamortized debt premiums, discounts and issuance costs	(142)	(171)
Long-term debt including amounts due currently	15,988	16,298
Accounts receivable financing	1,225	750
Forward repurchase obligation	1,314	1,335
Project-level debt
Debt Instrument [Line Items]
Long -term debt before unamortized premiums, discounts and issuance costs	1,488	1,064
Vistra Operations debt
Debt Instrument [Line Items]
Long -term debt before unamortized premiums, discounts and issuance costs	$ 14,642	$ 15,405