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COMMITMENTS AND CONTINGENCIES - Non-Cancellable Commitments under Purchase Commitment Contracts (Details) $ in Millions | 3 Months Ended
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Mar. 31, 2022 USD ($) megawatt
Offshore Wind Project |
Unrecorded Unconditional Purchase Obligation [Line Items] |
Contract term | 20 years
Energy capacity (in MW) | megawatt | 800
Renewable Energy | NSTAR Electric |
Unrecorded Unconditional Purchase Obligation [Line Items] |
2022 | $ 75.6
2023 | 78.3
2024 | 269.4
2025 | 315.8
2026 | 322.1
Thereafter | 5,812.2
Total | 6,873.4
Renewable Energy | NSTAR Electric | Massachusetts Clean Energy 83D Contract |
Unrecorded Unconditional Purchase Obligation [Line Items] |
Total | $ 6,000.0
Contract term | 20 years
Renewable Energy | NSTAR Electric | Minimum | Massachusetts Clean Energy 83D Contract |
Unrecorded Unconditional Purchase Obligation [Line Items] |
Estimated costs | $ 240.0
Renewable Energy | NSTAR Electric | Maximum | Massachusetts Clean Energy 83D Contract |
Unrecorded Unconditional Purchase Obligation [Line Items] |
Estimated costs | $ 375.0

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- Definition Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 440 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308 + Details
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- Definition Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 440 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308 + Details
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- Definition Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 440 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308 + Details
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