Debt, Credit Facilities and Financings - Schedule of Debt (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Long-term debt before unamortized premiums, discounts and issuance costs	$ 15,921	$ 16,469
Unamortized debt premiums, discounts, and issuance costs	(151)	(171)
Long-term debt including amounts due currently	15,770	16,298
Accounts receivable financing	1,125	750
Forward repurchase obligation	1,295	1,335
Short-term borrowings	861	0
Project-level debt
Debt Instrument [Line Items]
Long-term debt before unamortized premiums, discounts and issuance costs	1,273	1,064
Vistra Operations debt
Debt Instrument [Line Items]
Long-term debt before unamortized premiums, discounts and issuance costs	$ 14,648	$ 15,405