Summary of Significant Accounting Policies and Other Matters - Reconciliation of Cash, Temporary Investments and Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Line Items]
Cash and temporary cash investments	$ 1,282	$ 992
Restricted cash	223	154
Total cash, temporary cash investments and restricted cash	1,505	1,146
Cash Collateral Held For Project Finance Agreements \| Clean Energy Businesses
Cash and Cash Equivalents [Line Items]
Restricted cash	223	154
CECONY
Cash and Cash Equivalents [Line Items]
Cash and temporary cash investments	1,056	920
Restricted cash	0	0
Total cash, temporary cash investments and restricted cash	$ 1,056	$ 920

Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant