Debt, Credit Facilities, and Financings - Schedule of Long-Term Debt Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Total long-term debt including amounts due currently	$ 16,298	$ 14,402
Total other long-term debt	55	67
Unamortized premiums, discounts, and debt issuance costs	(171)	(115)
Less amounts due currently	(880)	(2,286)
Total long-term debt less amounts due currently	$ 15,418	12,116
Bridge Loan
Debt Instrument [Line Items]
Stated debt interest rate (percent)	1.625%
Vistra Operations Senior Secured Notes:
Debt Instrument [Line Items]
Total long-term debt including amounts due currently	$ 5,144	5,650
Energy Harbor Revenue Bonds
Debt Instrument [Line Items]
Total long-term debt including amounts due currently	431	0
Vistra Operations Senior Unsecured Notes:
Debt Instrument [Line Items]
Total long-term debt including amounts due currently	7,300	6,300
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	2,475	2,500
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	0
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	0
4.875% Senior Secured Notes, due May 13, 2024 | Vistra Operations Senior Secured Notes:
Debt Instrument [Line Items]
Total long-term debt including amounts due currently	$ 0	400
Stated debt interest rate (percent)	4.875%
3.550% Senior Secured Notes, due July 15, 2024 | Vistra Operations Senior Secured Notes:
Debt Instrument [Line Items]
Total long-term debt including amounts due currently	$ 0	1,500
Stated debt interest rate (percent)	3.55%
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	1,100
Stated debt interest rate (percent)	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	0
Stated debt interest rate (percent)	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
Stated debt interest rate (percent)	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
Stated debt interest rate (percent)	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
Stated debt interest rate (percent)	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	0
Stated debt interest rate (percent)	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	0
Stated debt interest rate (percent)	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	$ 0
Stated debt interest rate (percent)	3.375%	3.375%
4.750% Revenue Bond, due June 1, 2033 and July 1, 2023 | Energy Harbor Revenue Bonds
Debt Instrument [Line Items]
Total long-term debt including amounts due currently	$ 285	$ 0
Stated debt interest rate (percent)	4.75%	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	$ 0
Stated debt interest rate (percent)	3.75%	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
Stated debt interest rate (percent)	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
Stated debt interest rate (percent)	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
Stated debt interest rate (percent)	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
Stated debt interest rate (percent)	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
Stated debt interest rate (percent)	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	0
Stated debt interest rate (percent)	6.875%
Equipment Financing Agreements | Equipment Financing Agreements
Debt Instrument [Line Items]
Total long-term debt including amounts due currently	$ 55	$ 67