Represents the assumed rate of return for each class of pension and other post retirement benefit plan assets

No definition available.

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- Definition

Defined Benefit Plan, Health Care Trend Rate

+ References

No definition available.

+ Details

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- Definition

Defined Benefit Plan, Increase (Decrease) of Liability As A Result of Change in Discount Rate

+ References

No definition available.

+ Details

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- Definition

Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(3)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2919-114920

+ Details

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- Definition

Amount of contribution expected to be received by defined benefit plan from employer in next fiscal year following current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 18
-URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Ultimate trend rate for health care cost for defined benefit postretirement plan.

+ References

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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- Details

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- Details

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Balance Type:
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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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EMPLOYEE BENEFITS - Pension Plan Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Contribution Plan Disclosure [Line Items]
Expected long-term rate of return	7.00%	7.00%
Pension and SERP
Defined Contribution Plan Disclosure [Line Items]
Increase (decrease) in liability as a result of a change in discount rate	$ (1,480.0)	$ (286.8)
Expected long-term rate of return	8.25%	8.25%	8.25%
Estimated future employer contributions in next fiscal year	$ 5.0
PBOP
Defined Contribution Plan Disclosure [Line Items]
Increase (decrease) in liability as a result of a change in discount rate	$ (180.1)	$ (29.8)
Expected long-term rate of return	8.25%	8.25%	8.25%
Estimated future employer contributions in next fiscal year	$ 2.9
Pre-65 Plan \| PBOP
Defined Contribution Plan Disclosure [Line Items]
Health care trend rate	7.00%
Ultimate rate	5.00%
Pre-65 Plan \| Minimum \| PBOP \| Aquarion
Defined Contribution Plan Disclosure [Line Items]
Health care trend rate	3.50%	3.50%
Pre-65 Plan \| Maximum \| PBOP \| Aquarion
Defined Contribution Plan Disclosure [Line Items]
Health care trend rate	6.50%	6.20%
Post-65 Plan \| PBOP
Defined Contribution Plan Disclosure [Line Items]
Ultimate rate	3.50%
Eversource Service Pension and PBOP Plans
Defined Contribution Plan Disclosure [Line Items]
Assumed rate of return	8.25%
Aquarion Plans
Defined Contribution Plan Disclosure [Line Items]
Assumed rate of return	7.00%