Debt, Credit Facilities and Financings - Schedule of Long-Term Debt Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 16,305	$ 16,298
Total other long-term debt	55	55
Unamortized debt premiums, discounts and issuance costs	(158)	(171)
Less amounts due currently	(882)	(880)
Total long-term debt, less amounts due currently	$ 15,423	15,418
Bridge Loan
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	1.625%
Vistra Operations Senior Secured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 5,144	5,144
Energy Harbor Revenue Bonds
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	431	431
Vistra Operations Senior Unsecured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	7,300	7,300
Vistra Operations Credit Facilities, Term Loan B-3 Facility due December 20, 2030 | Line of Credit
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	2,469	2,475
BCOP Credit Facility, Tax Credit Bridge Loan due November 1, 2025 / December 3, 2026 | Bridge Loan
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	367	367
Vistra Zero Credit Facility, Term Loan B Facility due April 30, 2031 | Line of Credit
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	697	697
5.125% Senior Secured Notes, due May 13, 2025 | Vistra Operations Senior Secured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 744	744
Debt instrument, interest rate, stated percentage	5.125%
5.050% Senior Secured Notes, due December 30, 2026 | Vistra Operations Senior Secured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 500	500
Debt instrument, interest rate, stated percentage	5.05%
3.700% Senior Secured Notes, due January 30, 2027 | Vistra Operations Senior Secured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 800	800
Debt instrument, interest rate, stated percentage	3.70%
4.300% Senior Secured Notes, due July 15, 2029 | Vistra Operations Senior Secured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 800	800
Debt instrument, interest rate, stated percentage	4.30%
6.950% Senior Secured Notes, due October 15, 2033 | Vistra Operations Senior Secured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 1,050	1,050
Debt instrument, interest rate, stated percentage	6.95%
6.000% Senior Secured Notes, due April 15, 2034 | Vistra Operations Senior Secured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 500	500
Debt instrument, interest rate, stated percentage	6.00%
5.700% Senior Secured Notes, due December 30, 2034 | Vistra Operations Senior Secured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 750	750
Debt instrument, interest rate, stated percentage	5.70%
3.375% Revenue Bond, due August 1, 2029 | Energy Harbor Revenue Bonds
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 100	100
Debt instrument, interest rate, stated percentage	3.375%
4.750% Revenue Bonds, due June 1, 2033 and July 1, 2033 | Energy Harbor Revenue Bonds
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 285	285
Debt instrument, interest rate, stated percentage	4.75%
3.750% Revenue Bond, due October 1, 2047 | Energy Harbor Revenue Bonds
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 46	46
Debt instrument, interest rate, stated percentage	3.75%
5.500% Senior Unsecured Notes, due September 1, 2026 | Vistra Operations Senior Unsecured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 1,000	1,000
Debt instrument, interest rate, stated percentage	5.50%
5.625% Senior Unsecured Notes, due February 15, 2027 | Vistra Operations Senior Unsecured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 1,300	1,300
Debt instrument, interest rate, stated percentage	5.625%
5.000% Senior Unsecured Notes, due July 31, 2027 | Vistra Operations Senior Unsecured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 1,300	1,300
Debt instrument, interest rate, stated percentage	5.00%
4.375% Senior Unsecured Notes, due May 15, 2029 | Vistra Operations Senior Unsecured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 1,250	1,250
Debt instrument, interest rate, stated percentage	4.375%
7.750% Senior Unsecured Notes, due October 15, 2031 | Vistra Operations Senior Unsecured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 1,450	1,450
Debt instrument, interest rate, stated percentage	7.75%
6.875% Senior Unsecured Notes, due April 15, 2032 | Vistra Operations Senior Unsecured Notes
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 1,000	1,000
Debt instrument, interest rate, stated percentage	6.875%
Equipment Financing Agreements | Other Debt
Debt Instrument [Line Items]
Total long-term debt, including amounts due currently	$ 55	$ 55