Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income attributable to Vistra	$ 652	$ 1,888	$ 711	$ 2,218
Less cumulative dividends attributable to preferred stock	(48)	(48)	(144)	(144)
Net income attributable to Vistra common stock	$ 604	$ 1,840	$ 567	$ 2,074
Weighted average shares of common stock outstanding:
Weighted average shares of common stock outstanding - basic (in shares)	338,749,454	342,969,916	339,313,294	346,315,125
Dilutive securities: Stock-based incentive compensation plan	6,285,706	7,233,776	6,990,323	7,490,812
Weighted average shares of common stock outstanding - diluted (in shares)	345,035,160	350,203,692	346,303,617	353,805,937
Net income per weighted average share of common stock outstanding:
Net income per weighted average share of common stock outstanding - basic (in dollars per share)	$ 1.78	$ 5.36	$ 1.67	$ 5.99
Net income per weighted average share of common stock outstanding - diluted (in dollars per share)	$ 1.75	$ 5.25	$ 1.64	$ 5.86
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)	$ (60)	$ (60)
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)	(52)	(52)
Series C Preferred Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Less cumulative dividends attributable to preferred stock	$ (11)	$ (11)	$ (32)	$ (32)