Condensed Statements of Consolidated Changes in Equity (Unaudited) - Houston Electric - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	AOCI Attributable to Parent	Houston Electric	Houston Electric Common Stock	Houston Electric Additional Paid-in Capital	Houston Electric Retained Earnings	Houston Electric AOCI Attributable to Parent
Balance, beginning of period (in shares) at Dec. 31, 2020		551,000,000					1,000
Balance, beginning of period at Dec. 31, 2020		$ 6	$ 6,914	$ (845)	$ (90)		$ 0	$ 2,548	$ 563	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash contribution from parent						$ 0		0
Contribution from parent								0
Other								0
Net income	$ 614			614		156			156
Dividend to parent									0
Balance, end of period (in shares) at Jun. 30, 2021		593,000,000					1,000
Balance, end of period at Jun. 30, 2021	8,870	$ 6	7,553	(343)	(85)	3,267	$ 0	2,548	719	0
Balance, beginning of period (in shares) at Mar. 31, 2021		552,000,000					1,000
Balance, beginning of period at Mar. 31, 2021		$ 6	6,916	(482)	(87)		$ 0	2,548	616	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash contribution from parent						0		0
Contribution from parent								0
Other								0
Net income	251			251		103			103
Dividend to parent									0
Balance, end of period (in shares) at Jun. 30, 2021		593,000,000					1,000
Balance, end of period at Jun. 30, 2021	$ 8,870	$ 6	7,553	(343)	(85)	3,267	$ 0	2,548	719	0
Balance, beginning of period (in shares) at Dec. 31, 2021	628,923,534	629,000,000					1,000
Balance, beginning of period at Dec. 31, 2021	$ 9,415	$ 6	8,529	154	(64)	3,622	$ 0	2,678	944	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash contribution from parent						38		38
Contribution from parent								1,143
Other								1
Net income	$ 721			721		208			208
Dividend to parent									(67)
Balance, end of period (in shares) at Jun. 30, 2022	629,490,422	629,000,000					1,000
Balance, end of period at Jun. 30, 2022	$ 10,023	$ 6	8,544	768	(85)	4,945	$ 0	3,860	1,085	0
Balance, beginning of period (in shares) at Mar. 31, 2022		629,000,000					1,000
Balance, beginning of period at Mar. 31, 2022		$ 6	8,532	685	(62)		$ 0	3,354	968	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash contribution from parent						0		0
Contribution from parent								506
Other								0
Net income	$ 190			190		147			147
Dividend to parent									(30)
Balance, end of period (in shares) at Jun. 30, 2022	629,490,422	629,000,000					1,000
Balance, end of period at Jun. 30, 2022	$ 10,023	$ 6	$ 8,544	$ 768	$ (85)	$ 4,945	$ 0	$ 3,860	$ 1,085	$ 0