Condensed Statements of Consolidated Changes in Equity (Unaudited) - CERC - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in-Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Loss	CERC	CERC Common Stock	CERC Additional Paid-in-Capital	CERC Retained Earnings (Accumulated Deficit)	CERC Accumulated Other Comprehensive Loss
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	$ 3,966	$ 644	$ 10
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash contribution from parent						$ 0		0
Contribution from parent								0
Contribution to parent for sale of Arkansas and Oklahoma Natural Gas businesses						0		0
Other								(1)
Net income	$ 832			832		303			303
Dividend to parent									0
Balance, end of period (in shares) at Sep. 30, 2021		629,000,000					1,000
Balance, end of period at Sep. 30, 2021	8,865	$ 6	8,517	(368)	(80)	4,922	$ 0	3,965	947	10
Balance, beginning of period (in shares) at Jun. 30, 2021		593,000,000					1,000
Balance, beginning of period at Jun. 30, 2021		$ 6	7,553	(343)	(85)		$ 0	3,965	939	10
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash contribution from parent						0		0
Contribution from parent								0
Contribution to parent for sale of Arkansas and Oklahoma Natural Gas businesses						0		0
Other								0
Net income	218			218		8			8
Dividend to parent									0
Balance, end of period (in shares) at Sep. 30, 2021		629,000,000					1,000
Balance, end of period at Sep. 30, 2021	$ 8,865	$ 6	8,517	(368)	(80)	4,922	$ 0	3,965	947	10
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)	5,133	$ 0	4,106	1,017	10
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash contribution from parent						54		54
Contribution from parent								125
Contribution to parent for sale of Arkansas and Oklahoma Natural Gas businesses						720		(720)
Other								0
Net income	$ 923			923		656			656
Dividend to parent									(124)
Balance, end of period (in shares) at Sep. 30, 2022	629,532,024	629,000,000					1,000
Balance, end of period at Sep. 30, 2022	$ 9,989	$ 6	8,557	719	(83)	5,124	$ 0	3,565	1,549	10
Balance, beginning of period (in shares) at Jun. 30, 2022		629,000,000					1,000
Balance, beginning of period at Jun. 30, 2022		$ 6	8,544	768	(85)		$ 0	3,565	1,569	10
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash contribution from parent						0		0
Contribution from parent								0
Contribution to parent for sale of Arkansas and Oklahoma Natural Gas businesses						0		0
Other								0
Net income	$ 202			202		(7)			(7)
Dividend to parent									(13)
Balance, end of period (in shares) at Sep. 30, 2022	629,532,024	629,000,000					1,000
Balance, end of period at Sep. 30, 2022	$ 9,989	$ 6	$ 8,557	$ 719	$ (83)	$ 5,124	$ 0	$ 3,565	$ 1,549	$ 10