DERIVATIVE INSTRUMENTS - Variations Using Significant unobservable Inputs (Details) - NSTAR Electric - Level 3 - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended |
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Jun. 30, 2026 |
Jun. 30, 2026 |
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| Derivatives, Net [Rollforward] | ||
| Fair Value as of Beginning of Period | $ (505.0) | $ (662.1) |
| Net Realized/Unrealized Gains Included in Regulatory Assets and Liabilities | 218.3 | 438.8 |
| Settlements | 11.5 | (51.9) |
| Fair Value as of End of Period | $ (275.2) | $ (275.2) |
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- Definition Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Liability Gain (Loss) Included In Regulatory Asset Liability No definition available.
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- Definition Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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