Condensed Statements of Consolidated Changes in Equity (Unaudited) - CERC - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in-Capital	Retained Earnings	Accumulated Other Comprehensive Loss	CERC	CERC Common Stock	CERC Additional Paid-in-Capital	CERC Retained Earnings	CERC Accumulated Other Comprehensive Loss
Balance, beginning of period (in shares) at Dec. 31, 2021		629,000,000					1,000
Balance, beginning of period at Dec. 31, 2021		$ 6	$ 8,529	$ 154	$ (64)		$ 0	$ 4,106	$ 1,017	$ 10
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash contribution from parent						$ 54		54
Contribution to parent for sale of Arkansas and Oklahoma Natural Gas businesses						720		(720)
Net income	$ 531			531		631			631
Dividend to parent									(38)
Other comprehensive loss					2					0
Balance, end of period (in shares) at Mar. 31, 2022		629,000,000					1,000
Balance, end of period at Mar. 31, 2022	$ 9,951	$ 6	8,532	685	(62)	5,060	$ 0	3,440	1,610	10
Balance, beginning of period (in shares) at Dec. 31, 2022	629,535,631	630,000,000					1,000
Balance, beginning of period at Dec. 31, 2022	$ 10,042	$ 6	8,568	709	(31)	5,363	$ 0	3,729	1,618	16
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash contribution from parent						0		0
Contribution to parent for sale of Arkansas and Oklahoma Natural Gas businesses						0		0
Net income	$ 325			325		212			212
Dividend to parent									(204)
Other comprehensive loss					(1)					(1)
Balance, end of period (in shares) at Mar. 31, 2023	631,018,976	631,000,000					1,000
Balance, end of period at Mar. 31, 2023	$ 10,356	$ 6	$ 8,558	$ 1,034	$ (32)	$ 5,370	$ 0	$ 3,729	$ 1,626	$ 15