Capitalization - Carrying Amounts and Fair Values of Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Unamortized debt expense	$ 223	$ 226
Carrying Amount
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	23,022	23,044
Fair Value
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	23,812	26,287
CECONY \| Subsidiaries
Debt Instrument [Line Items]
Unamortized debt discount	191	193
CECONY \| Carrying Amount \| Subsidiaries
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	18,384	18,382
CECONY \| Fair Value \| Subsidiaries
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	$ 19,175	$ 21,382

Amount, after accumulated amortization, of debt discount.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
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