Short-term Borrowings and Long-term Debt - Early Extinguishment of Debt (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Losses on early extinguishment of debt	$ 11	$ 47	$ 53
CERC Corp
Debt Instrument [Line Items]
Losses on early extinguishment of debt	0	0	11
Houston Electric
Debt Instrument [Line Items]
Losses on early extinguishment of debt	$ 0	$ 2	$ 0