Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Cash Payments/Receipts:
Interest, net of capitalized interest	$ 191	$ 134
Income tax refunds, net	(1)	(15)
Non-cash transactions:
Accounts payable related to capital expenditures	270	307
ROU assets obtained in exchange for lease liabilities	1	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	114		$ 74
Restricted cash included in Prepaid expenses and other current assets	16		17
Total cash, cash equivalents and restricted cash shown in Condensed Statements of Consolidated Cash Flows	130	147	91	$ 254
Houston Electric
Cash Payments/Receipts:
Interest, net of capitalized interest	78	63
Income tax refunds, net	0	0
Non-cash transactions:
Accounts payable related to capital expenditures	178	232
ROU assets obtained in exchange for lease liabilities	1	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	112		75
Restricted cash included in Prepaid expenses and other current assets	12		13
Total cash, cash equivalents and restricted cash shown in Condensed Statements of Consolidated Cash Flows	124	122	88	233
Houston Electric | Bond Companies
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	110		75
CERC
Cash Payments/Receipts:
Interest, net of capitalized interest	58	33
Income tax refunds, net	0	0
Non-cash transactions:
Accounts payable related to capital expenditures	85	92
ROU assets obtained in exchange for lease liabilities	0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	1		0
Restricted cash included in Prepaid expenses and other current assets	0		0
Total cash, cash equivalents and restricted cash shown in Condensed Statements of Consolidated Cash Flows	$ 1	$ 5	$ 0	$ 15