Revenue Recognition - Schedule of Bad Debt Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Bad debt expense	$ 18	$ 20	$ 12
Bad debt expense deferred as regulatory asset	0	0	16
Houston Electric
Bad debt expense	0	0	0
Bad debt expense deferred as regulatory asset	0	0	8
CERC Corp
Bad debt expense	16	17	10
Bad debt expense deferred as regulatory asset	$ 0	$ 0	$ 8