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Environmental Matters - Additional Information (Details) $ in Millions | 12 Months Ended
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Dec. 31, 2020 USD ($)
Asbestos Proceedings |
Site Contingency [Line Items] |
Estimated undiscounted asbestos liability (years) | 15 years
CECONY | Asbestos Proceedings |
Site Contingency [Line Items] |
Estimated undiscounted asbestos liability (years) | 15 years
Superfund Sites |
Site Contingency [Line Items] |
Remediation cost estimate | $ 40
Superfund Sites | Manufactured Gas Plant Sites | Maximum |
Site Contingency [Line Items] |
Estimated aggregate undiscounted potential liability related environmental contaminants (up to) | 2,700
Superfund Sites | CECONY |
Site Contingency [Line Items] |
Remediation cost estimate | 38
Superfund Sites | CECONY | Manufactured Gas Plant Sites | Maximum |
Site Contingency [Line Items] |
Estimated aggregate undiscounted potential liability related environmental contaminants (up to) | $ 2,600

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