Short-term Borrowings and Long-term Debt - Schedule of Maturities (Details) $ in Millions	Dec. 31, 2023 USD ($)
Houston Electric
Debt Instrument [Line Items]
2024	$ 161
2025	0
2026	300
2027	300
2028	500
CERC Corp
Debt Instrument [Line Items]
2024	0
2025	10
2026	60
2027	510
2028	1,230
Long term Debt Excluding ZENS
Debt Instrument [Line Items]
2024	1,050
2025	64
2026	2,274
2027	1,860
2028	2,063
Securitization Bonds
Debt Instrument [Line Items]
2024	178
2025	13
2026	14
2027	14
2028	$ 15

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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