Fair Value Measurements - Schedule of Fair Value of Debt (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Carrying Amount | Vistra Operations Credit Facilities, Term Loan B-3 Facility due December 20, 2030 | Level 2
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	$ 2,435	$ 2,456
Carrying Amount | BCOP Credit Facilities Tax Credit Bridge Loan | Level 3
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	344	0
Carrying Amount | Vistra Zero Term Loan B Facility | Level 2
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	685	0
Carrying Amount | Vistra Operations Senior Notes | Level 2
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	12,366	11,881
Carrying Amount | Energy Harbor Revenue Bonds | Level 2
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	414	0
Carrying Amount | Equipment Financing Agreements | Level 3
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	54	65
Carrying Amount | Forward Repurchase Obligation | Level 3
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	1,335	0
Fair Value | Vistra Operations Credit Facilities, Term Loan B-3 Facility due December 20, 2030 | Level 2
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	2,478	2,500
Fair Value | BCOP Credit Facilities Tax Credit Bridge Loan | Level 3
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	367	0
Fair Value | Vistra Zero Term Loan B Facility | Level 2
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	697	0
Fair Value | Vistra Operations Senior Notes | Level 2
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	12,428	11,752
Fair Value | Energy Harbor Revenue Bonds | Level 2
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	431	0
Fair Value | Equipment Financing Agreements | Level 3
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	53	62
Fair Value | Forward Repurchase Obligation | Level 3
Debt Instrument [Line Items]
Debt Instrument, fair value disclosure	$ 1,335	$ 0