Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income attributable to Vistra	$ 327	$ 365	$ 59	$ 330
Less cumulative dividends attributable to preferred stock	(47)	(47)	(96)	(96)
Net income (loss) attributable to Vistra common stock	280	318	(37)	234
Net income attributable to Vistra common stock	$ 280	$ 318	$ (37)	$ 234
Weighted average shares of common stock outstanding:
Weighted average shares of common stock outstanding - basic (in shares)	339,401,983	347,046,021	339,599,887	348,006,109
Dilutive securities - stock-based incentive compensation plan	6,103,205	7,281,372	0	7,549,320
Weighted average shares of common stock outstanding - diluted (in shares)	345,505,188	354,327,393	339,599,887	355,555,429
Net income (loss) per weighted average share of common stock outstanding:
Net income per weighted average share of common stock outstanding - basic (in dollars per share)	$ 0.82	$ 0.92	$ (0.11)	$ 0.67
Net income per weighted average share of common stock outstanding - diluted (in dollars per share)	$ 0.81	$ 0.90	$ (0.11)	$ 0.66
Series A Preferred Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Less cumulative dividends attributable to preferred stock	$ (20)	$ (20)	$ (40)	$ (40)
Series B Preferred Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Less cumulative dividends attributable to preferred stock	(17)	(17)	(35)	(35)
Series C Preferred Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Less cumulative dividends attributable to preferred stock	$ (10)	$ (10)	$ (21)	$ (21)