Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Cash Payments/Receipts:
Interest, net of capitalized interest	$ 376	$ 427
Income tax payments (refunds), net	340	(47)
Non-cash transactions:
Accounts payable related to capital expenditures	333	290
ROU assets obtained in exchange for lease liabilities	1	2
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	114		$ 230
Restricted cash included in Prepaid expenses and other current assets	16		24
Total cash, cash equivalents and restricted cash shown in Condensed Statements of Consolidated Cash Flows	130	156	254	$ 167
Houston Electric
Cash Payments/Receipts:
Interest, net of capitalized interest	188	172
Income tax payments (refunds), net	113	0
Non-cash transactions:
Accounts payable related to capital expenditures	197	208
ROU assets obtained in exchange for lease liabilities	0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	115		214
Restricted cash included in Prepaid expenses and other current assets	12		19
Total cash, cash equivalents and restricted cash shown in Condensed Statements of Consolidated Cash Flows	127	123	233	154
Houston Electric | Bond Companies
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	110		92
CERC
Cash Payments/Receipts:
Interest, net of capitalized interest	67	96
Income tax payments (refunds), net	3	(11)
Non-cash transactions:
Accounts payable related to capital expenditures	145	124
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		15
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	$ 1	$ 15	$ 6