Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Preferred Stock Dividends and Other Adjustments [Abstract]
Preferred stock dividend requirement	$ 0	$ 12	$ 0	$ 24
Total income allocated to preferred shareholders	0	12	0	24
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(33)	(32)	(35)	(31)
Net deferred gain from cash flow hedges	1	0	4	0
Prior service cost	2	0	2	(1)
Actuarial losses			1	0
Other comprehensive income (loss)	3	0	5	(1)
Ending Balance	(30)	(32)	(30)	(32)
CERC
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	15	15	16	16
Net deferred gain from cash flow hedges	0	0	0	0
Prior service cost	0	0	0	(1)
Actuarial losses			(1)	0
Other comprehensive income (loss)	0	0	(1)	(1)
Ending Balance	$ 15	$ 15	15	15
Other Pension, Postretirement and Supplemental Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Remeasurement of pension and other postretirement plans			(2)	0
Other Pension, Postretirement and Supplemental Plans | CERC
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Remeasurement of pension and other postretirement plans			$ 0	$ 0
Common Stock
Class of Stock [Line Items]
Common stock, dividends declared per share (in dollars per share)	$ 0.200	$ 0.190	$ 0.200	$ 0.190
Common Stock dividends paid per share (in dollars per share)	0.200	0.190	0.400	0.380
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividends declared (in dollars per share)	0	0	0	0
Preferred stock dividends paid per share (in dollars per share)	$ 0	$ 0	$ 0	$ 30.625
Preferred Stock Dividends and Other Adjustments [Abstract]
Preferred stock dividend requirement	$ 0	$ 12	$ 0	$ 24