Condensed Statements of Consolidated Changes in Equity - 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]
Contribution from parent								0
Other								0
Net income	$ 363			363		$ 53			53
Dividend to parent									0
Balance, end of period (in shares) at Mar. 31, 2021		552,000,000					1,000
Balance, end of period at Mar. 31, 2021	$ 8,716	$ 6	6,916	(482)	(87)	3,164	$ 0	2,548	616	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]
Contribution from parent								675
Other								1
Net income	$ 531			531		61			61
Dividend to parent									(37)
Balance, end of period (in shares) at Mar. 31, 2022	629,432,406	629,000,000					1,000
Balance, end of period at Mar. 31, 2022	$ 9,951	$ 6	$ 8,532	$ 685	$ (62)	$ 4,322	$ 0	$ 3,354	$ 968	$ 0