Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-4

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-4

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-4

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-4

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Material Contingencies - Guarantees (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Guarantor Obligations [Line Items]
Total guarantees, by type and term	$ 58	$ 58
Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	58
0 – 3 years
Guarantor Obligations [Line Items]
Total guarantees, by type and term	58
0 – 3 years \| Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	$ 58