NSTAR Electric (NSARO) 10-K 15 Feb 23 2022 FY Annual report Financial data

COVER PAGE

COVER PAGE - USD ($)	12 Months Ended
	Dec. 31, 2022	Jan. 31, 2023	Jun. 30, 2022
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity Registrant Name	EVERSOURCE ENERGY
Entity Incorporation, State or Country Code	MA
Entity Address, Address Line One	300 Cadwell Drive
Entity Address, City or Town	Springfield
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01104
City Area Code	800
Local Phone Number	286-5000
Entity File Number	001-05324
Entity Tax Identification Number	04-2147929
Title of 12(b) Security	Common Shares, $5.00 par value per share
Trading Symbol	ES
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 29,211,450,455
Entity Common Stock, Shares Outstanding		348,483,425
Documents Incorporated by Reference	Documents Incorporated by Reference Portions of the Eversource Energy and Subsidiaries 2021 combined Annual Report on Form 10-K and portions of the Proxy Statement relating to the Annual Meeting of Shareholders to be held on May 3, 2023, are incorporated by reference into Parts II and III of this Report.
Entity Central Index Key	0000072741
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
The Connecticut Light and Power Company
Entity Information [Line Items]
Current Fiscal Year End Date	--12-31
Entity Registrant Name	THE CONNECTICUT LIGHT AND POWER COMPANY
Entity Incorporation, State or Country Code	CT
Entity Address, Address Line One	107 Selden Street
Entity Address, City or Town	Berlin
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06037-1616
City Area Code	800
Local Phone Number	286-5000
Entity File Number	000-00404
Entity Tax Identification Number	06-0303850
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		6,035,205
Entity Central Index Key	0000023426
NSTAR Electric Company
Entity Information [Line Items]
Current Fiscal Year End Date	--12-31
Entity Registrant Name	NSTAR ELECTRIC COMPANY
Entity Incorporation, State or Country Code	MA
Entity Address, Address Line One	800 Boylston Street
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02199
City Area Code	800
Local Phone Number	286-5000
Entity File Number	001-02301
Entity Tax Identification Number	04-1278810
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		200
Entity Central Index Key	0000013372
Public Service Company of New Hampshire
Entity Information [Line Items]
Current Fiscal Year End Date	--12-31
Entity Registrant Name	PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE
Entity Incorporation, State or Country Code	NH
Entity Address, Address Line One	Energy Park
Entity Address, Address Line Two	780 North Commercial Street
Entity Address, City or Town	Manchester
Entity Address, State or Province	NH
Entity Address, Postal Zip Code	03101-1134
City Area Code	800
Local Phone Number	286-5000
Entity File Number	001-06392
Entity Tax Identification Number	02-0181050
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		301
Entity Central Index Key	0000315256

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2022
Auditor [Line Items]
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Hartford, Connecticut
CL&P
Auditor [Line Items]
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Hartford, Connecticut
NSTAR Electric
Auditor [Line Items]
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Hartford, Connecticut
PSNH
Auditor [Line Items]
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Hartford, Connecticut

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current Assets:
Cash	$ 47,597	$ 66,773
Cash Equivalents	327,006	0
Receivables, Net (net of allowance for uncollectible accounts)	1,517,138	1,226,069
Unbilled Revenues	238,968	210,879
Materials, Supplies, Natural Gas and REC Inventory	374,395	267,547
Regulatory Assets	1,335,491	1,129,093
Prepayments and Other Current Assets	382,603	369,759
Total Current Assets	4,223,198	3,270,120
Property, Plant and Equipment, Net	36,112,820	33,377,650
Deferred Debits and Other Assets:
Regulatory Assets	4,242,794	4,586,709
Goodwill	4,522,632	4,477,269
Investments in Unconsolidated Affiliates	2,176,080	1,436,293
Prepaid Pension and PBOP	1,045,524	271,987
Marketable Securities	366,508	460,347
Other Long-Term Assets	541,344	611,769
Total Deferred Debits and Other Assets	12,894,882	11,844,374
Total Assets	53,230,900	48,492,144
Current Liabilities:
Notes Payable	1,442,200	1,505,450
Long-Term Debt – Current Portion	1,320,129	1,193,097
Rate Reduction Bonds – Current Portion	43,210	43,210
Accounts Payable	2,113,905	1,672,230
Regulatory Liabilities	890,786	602,432
Other Current Liabilities	989,053	830,620
Total Current Liabilities	6,799,283	5,847,039
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	5,067,902	4,597,120
Regulatory Liabilities	3,930,305	3,866,251
Derivative Liabilities	143,929	235,387
Asset Retirement Obligations	502,713	500,111
Accrued Pension, SERP and PBOP	135,473	242,463
Other Long-Term Liabilities	888,081	971,080
Total Deferred Credits and Other Liabilities	10,668,403	10,412,412
Capitalization:
Long-Term Debt	19,723,994	17,023,577
Rate Reduction Bonds	410,492	453,702
Noncontrolling Interest - Preferred Stock of Subsidiaries	155,570	155,570
Common Shareholders' Equity:
Common Shares	1,799,920	1,789,092
Capital Surplus, Paid In	8,401,731	8,098,514
Retained Earnings	5,527,153	5,005,391
Accumulated Other Comprehensive Income/(Loss)	(39,421)	(42,275)
Treasury Stock	(216,225)	(250,878)
Common Shareholders' Equity	15,473,158	14,599,844
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	$ 53,230,900	$ 48,492,144

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for uncollectible accounts	$ 486,297	$ 417,406	$ 358,900	$ 224,800

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Operating Revenues	$ 12,289,336	$ 9,863,085	$ 8,904,430
Operating Expenses:
Purchased Power, Purchased Natural Gas and Transmission	5,014,074	3,372,344	2,987,840
Operations and Maintenance	1,865,328	1,739,685	1,480,252
Depreciation	1,194,246	1,103,008	981,380
Amortization	448,892	231,965	177,679
Energy Efficiency Programs	658,051	592,775	535,760
Taxes Other Than Income Taxes	910,591	829,987	752,785
Total Operating Expenses	10,091,182	7,869,764	6,915,696
Operating Income	2,198,154	1,993,321	1,988,734
Interest Expense	678,274	582,334	538,452
Other Income, Net	346,088	161,282	108,590
Income Before Income Tax Expense	1,865,968	1,572,269	1,558,872
Income Tax Expense	453,574	344,223	346,186
Net Income	1,412,394	1,228,046	1,212,686
Net Income Attributable to Noncontrolling Interests	7,519	7,519	7,519
Net Income Attributable to Common Shareholders	$ 1,404,875	$ 1,220,527	$ 1,205,167
Basic Earnings Per Common Share (in dollars per share)	$ 4.05	$ 3.55	$ 3.56
Diluted Earnings Per Common Share (in dollars per share)	$ 4.05	$ 3.54	$ 3.55
Weighted Average Common Shares Outstanding:
Basic (in shares)	346,783,444	343,972,926	338,836,147
Diluted (in shares)	347,246,768	344,631,056	339,847,062

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	20	972	1,596
Changes in Unrealized (Losses)/Gains on Marketable Securities	(1,636)	(671)	342
Changes in Funded Status of Pension, SERP and PBOP Benefit Plans	4,470	33,835	(13,290)
Other Comprehensive Income/(Loss), Net of Tax	2,854	34,136	(11,352)
Comprehensive Income Attributable to Noncontrolling Interests	(7,519)	(7,519)	(7,519)
Comprehensive Income Attributable to Common Shareholders	$ 1,407,729	$ 1,254,663	$ 1,193,815

CONSOLIDATED STATEMENTS OF COMM

CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Adoption of New Accounting Standard	Common Shares	Capital Surplus, Paid In	Retained Earnings	Retained Earnings Adoption of New Accounting Standard	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning balance (in shares) at Dec. 31, 2019			329,880,645
Beginning balance at Dec. 31, 2019	$ 12,629,994	$ (1,514)	$ 1,729,292	$ 7,087,768	$ 4,177,048	$ (1,514)	$ (65,059)	$ (299,055)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,212,686				1,212,686
Dividends on Common Stock	(767,500)				(767,500)
Dividends on Preferred Stock	(7,519)				(7,519)
Issuance of Common Shares (in shares)			11,960,000
Issuance of Common Shares	949,660		$ 59,800	889,860
Long-Term Incentive Plan Activity	7,890			7,890
Issuance of Treasury Shares (in shares)			1,113,378
Issuance of Treasury Shares	71,888			50,812				21,076
Capital Stock Expense	(20,667)			(20,667)
Other Comprehensive Income/(Loss), Net of Tax	(11,352)						(11,352)
Ending balance (in shares) at Dec. 31, 2020			342,954,023
Ending balance at Dec. 31, 2020	14,063,566		$ 1,789,092	8,015,663	4,613,201		(76,411)	(277,979)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,228,046				1,228,046
Dividends on Common Stock	(828,337)				(828,337)
Dividends on Preferred Stock	(7,519)				(7,519)
Long-Term Incentive Plan Activity	3,537			3,537
Issuance of Treasury Shares (in shares)			986,656
Issuance of Treasury Shares	68,364			49,913				18,451
Issuance of Treasury Shares for Acquisition (in shares)			462,517
Issuance of Treasury Shares for Acquisition	38,051			29,401				8,650
Other Comprehensive Income/(Loss), Net of Tax	$ 34,136						34,136
Ending balance (in shares) at Dec. 31, 2021	344,403,196		344,403,196
Ending balance at Dec. 31, 2021	$ 14,599,844		$ 1,789,092	8,098,514	5,005,391		(42,275)	(250,878)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,412,394				1,412,394
Dividends on Common Stock	(883,113)				(883,113)
Dividends on Preferred Stock	(7,519)				(7,519)
Issuance of Common Shares (in shares)			2,165,671
Issuance of Common Shares	199,905		$ 10,828	189,077
Long-Term Incentive Plan Activity	8,335			8,335
Issuance of Treasury Shares (in shares)			949,724
Issuance of Treasury Shares	71,172			53,822				17,350
Capital Stock Expense	(2,847)			(2,847)
Issuance of Treasury Shares for Acquisition (in shares)			925,264
Issuance of Treasury Shares for Acquisition	72,133			54,830
Other Comprehensive Income/(Loss), Net of Tax	$ 2,854						2,854
Ending balance (in shares) at Dec. 31, 2022	348,443,855		348,443,855
Ending balance at Dec. 31, 2022	$ 15,473,158		$ 1,799,920	$ 8,401,731	$ 5,527,153		$ (39,421)	$ (216,225)

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Stockholders' Equity [Abstract]
Dividends on Common Shares (in dollars per share)	$ 2.55	$ 2.41	$ 2.27
Par value of Common Shares (in dollars per share)	$ 5	$ 5	$ 5

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Depreciation	1,194,246	1,103,008	981,380
Deferred Income Taxes	346,779	347,056	257,154
Uncollectible Expense	61,876	60,886	53,461
Pension, SERP and PBOP (Income)/Expense, Net	(160,857)	(14,693)	12,888
Pension and PBOP Contributions	(83,148)	(182,344)	(111,524)
Regulatory Under Recoveries, Net	(205,294)	(314,211)	(516,411)
(Customer Credits)/Reserve at CL&P related to PURA Settlement Agreement and Storm Performance Penalty	(72,041)	81,274	0
Amortization	448,892	231,965	177,679
Cost of Removal Expenditures	(303,755)	(242,130)	(148,332)
Payment of Withheld Property Taxes	(78,446)	0	0
Other	(39,192)	(64,640)	(25,957)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(470,593)	(135,505)	(351,843)
Taxes Receivable/Accrued, Net	18,358	(110,621)	43,819
Accounts Payable	377,657	(29,201)	122,567
Other Current Assets and Liabilities, Net	(45,583)	3,710	(24,995)
Net Cash Flows Provided by Operating Activities	2,401,293	1,962,600	1,682,572
Investing Activities:
Investments in Property, Plant and Equipment	(3,441,852)	(3,175,080)	(2,942,996)
Proceeds from Sales of Marketable Securities	457,612	447,893	434,124
Purchases of Marketable Securities	(424,174)	(414,980)	(401,823)
Acquisition of Assets of Columbia Gas of Massachusetts, Net of Restricted Cash	0	0	(1,113,252)
Investments in Unconsolidated Affiliates	(742,496)	(327,385)	(239,673)
Other Investing Activities	20,420	22,178	23,809
Net Cash Flows Used in Investing Activities	(4,130,490)	(3,447,374)	(4,129,275)
Financing Activities:
Issuance of Common Shares, Net of Issuance Costs	197,058	0	928,992
Cash Dividends on Common Shares	(860,033)	(805,439)	(744,665)
Cash Dividends on Preferred Stock	(7,519)	(7,519)	(7,519)
(Decrease)/Increase in Notes Payable	(78,170)	256,125	13,955
Repayment of Rate Reduction Bonds	(43,210)	(43,210)	(43,210)
Issuance of Long-Term Debt	4,045,000	3,230,000	2,760,000
Retirement of Long-Term Debt	(1,175,000)	(1,142,500)	(327,236)
Other Financing Activities	(48,185)	(46,625)	14,273
Net Cash Flows Provided by Financing Activities	2,029,941	1,440,832	2,594,590
Net Increase/(Decrease) in Cash, Cash Equivalents and Restricted Cash	300,744	(43,942)	147,887
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	221,008	264,950	117,063
Cash, Cash Equivalents and Restricted Cash - End of Year	521,752	221,008	264,950
Hingham Water System
Investing Activities:
Proceeds from the Sale of Hingham Water System	$ 0	$ 0	$ 110,536

THE CONNECTICUT LIGHT AND POWER

THE CONNECTICUT LIGHT AND POWER COMPANY BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current Assets:
Cash	$ 47,597	$ 66,773
Receivables, Net (net of allowance for uncollectible accounts)	1,517,138	1,226,069
Unbilled Revenues	238,968	210,879
Materials, Supplies, Natural Gas and REC Inventory	374,395	267,547
Regulatory Assets	1,335,491	1,129,093
Prepayments and Other Current Assets	382,603	369,759
Total Current Assets	4,223,198	3,270,120
Property, Plant and Equipment, Net	36,112,820	33,377,650
Deferred Debits and Other Assets:
Regulatory Assets	4,242,794	4,586,709
Prepaid Pension	1,045,524	271,987
Other Long-Term Assets	541,344	611,769
Total Deferred Debits and Other Assets	12,894,882	11,844,374
Total Assets	53,230,900	48,492,144
Current Liabilities:
Accounts Payable	2,113,905	1,672,230
Regulatory Liabilities	890,786	602,432
Other Current Liabilities	989,053	830,620
Total Current Liabilities	6,799,283	5,847,039
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	5,067,902	4,597,120
Regulatory Liabilities	3,930,305	3,866,251
Derivative Liabilities	143,929	235,387
Accrued Pension, SERP and PBOP	135,473	242,463
Other Long-Term Liabilities	888,081	971,080
Total Deferred Credits and Other Liabilities	10,668,403	10,412,412
Capitalization:
Long-Term Debt	19,723,994	17,023,577
Noncontrolling Interest - Preferred Stock of Subsidiaries	155,570	155,570
Common Shareholders' Equity:
Capital Surplus, Paid In	8,401,731	8,098,514
Retained Earnings	5,527,153	5,005,391
Accumulated Other Comprehensive Income/(Loss)	(39,421)	(42,275)
Common Shareholders' Equity	15,473,158	14,599,844
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	53,230,900	48,492,144
The Connecticut Light and Power Company
Current Assets:
Cash	11,312	55,804
Receivables, Net (net of allowance for uncollectible accounts)	612,052	447,774
Accounts Receivable from Affiliated Companies	46,439	43,944
Unbilled Revenues	59,363	56,787
Materials, Supplies, Natural Gas and REC Inventory	88,157	60,264
Taxes Receivable	65,785	55,223
Regulatory Assets	314,089	371,609
Prepayments and Other Current Assets	62,524	65,034
Total Current Assets	1,259,721	1,156,439
Property, Plant and Equipment, Net	11,467,024	10,803,543
Deferred Debits and Other Assets:
Regulatory Assets	1,593,693	1,713,161
Prepaid Pension	147,914	429
Other Long-Term Assets	290,444	276,084
Total Deferred Debits and Other Assets	2,032,051	1,989,674
Total Assets	14,758,796	13,949,656
Current Liabilities:
Accounts Payable	710,500	533,454
Accounts Payable to Affiliated Companies	136,277	132,578
Regulatory Liabilities	336,048	266,489
Derivative Liabilities	81,588	73,528
Other Current Liabilities	163,875	141,955
Total Current Liabilities	1,428,288	1,148,004
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	1,640,034	1,562,102
Regulatory Liabilities	1,263,396	1,193,259
Derivative Liabilities	143,929	235,387
Accrued Pension, SERP and PBOP	12,887	26,820
Other Long-Term Liabilities	153,194	153,004
Total Deferred Credits and Other Liabilities	3,213,440	3,170,572
Capitalization:
Long-Term Debt	4,216,488	4,215,379
Noncontrolling Interest - Preferred Stock of Subsidiaries	116,200	116,200
Common Shareholders' Equity:
Common Shares	60,352	60,352
Capital Surplus, Paid In	3,260,765	3,010,765
Retained Earnings	2,463,094	2,228,133
Accumulated Other Comprehensive Income/(Loss)	169	251
Common Shareholders' Equity	5,784,380	5,299,501
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	$ 14,758,796	$ 13,949,656

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for uncollectible accounts	$ 486,297	$ 417,406	$ 358,900	$ 224,800
CL&P
Allowance for uncollectible accounts	$ 225,320	$ 181,319	$ 157,400	$ 97,300

THE CONNECTICUT LIGHT AND POW_2

THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Revenues	$ 12,289,336	$ 9,863,085	$ 8,904,430
Operating Expenses:
Purchased Power and Transmission	5,014,074	3,372,344	2,987,840
Operations and Maintenance	1,865,328	1,739,685	1,480,252
Depreciation	1,194,246	1,103,008	981,380
Energy Efficiency Programs	658,051	592,775	535,760
Taxes Other Than Income Taxes	910,591	829,987	752,785
Total Operating Expenses	10,091,182	7,869,764	6,915,696
Operating Income	2,198,154	1,993,321	1,988,734
Interest Expense	678,274	582,334	538,452
Other Income, Net	346,088	161,282	108,590
Income Before Income Tax Expense	1,865,968	1,572,269	1,558,872
Income Tax Expense	453,574	344,223	346,186
Net Income	1,412,394	1,228,046	1,212,686
The Connecticut Light and Power Company
Operating Revenues	4,817,744	3,637,412	3,547,527
Operating Expenses:
Purchased Power and Transmission	2,110,253	1,392,969	1,369,196
Operations and Maintenance	707,162	644,175	572,897
Depreciation	355,511	338,915	320,709
Amortization of Regulatory Assets, Net	335,636	99,009	58,412
Energy Efficiency Programs	134,222	129,564	141,453
Taxes Other Than Income Taxes	384,746	363,862	344,451
Total Operating Expenses	4,027,530	2,968,494	2,807,118
Operating Income	790,214	668,918	740,409
Interest Expense	169,348	166,107	153,547
Other Income, Net	83,252	30,187	20,774
Income Before Income Tax Expense	704,118	532,998	607,636
Income Tax Expense	171,198	131,273	149,702
Net Income	$ 532,920	$ 401,725	$ 457,934

THE CONNECTICUT LIGHT AND POW_3

THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	20	972	1,596
Changes in Unrealized (Losses)/Gains on Marketable Securities	(1,636)	(671)	342
Other Comprehensive Income/(Loss), Net of Tax	2,854	34,136	(11,352)
Comprehensive Income Attributable to Common Shareholders	1,407,729	1,254,663	1,193,815
The Connecticut Light and Power Company
Net Income	532,920	401,725	457,934
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	(26)	(26)	(26)
Changes in Unrealized (Losses)/Gains on Marketable Securities	(56)	(25)	12
Other Comprehensive Income/(Loss), Net of Tax	(82)	(51)	(14)
Comprehensive Income Attributable to Common Shareholders	$ 532,838	$ 401,674	$ 457,920

THE CONNECTICUT LIGHT AND POW_4

THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Thousands	Total	Adoption of New Accounting Standard	Common Stock	Capital Surplus, Paid In	Retained Earnings	Retained Earnings Adoption of New Accounting Standard	Accumulated Other Comprehensive Income (Loss)	The Connecticut Light and Power Company	The Connecticut Light and Power Company Adoption of New Accounting Standard	The Connecticut Light and Power Company Common Stock	The Connecticut Light and Power Company Capital Surplus, Paid In	The Connecticut Light and Power Company Retained Earnings	The Connecticut Light and Power Company Retained Earnings Adoption of New Accounting Standard	The Connecticut Light and Power Company Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2019			329,880,645							6,035,205
Beginning balance at Dec. 31, 2019	$ 12,629,994	$ (1,514)	$ 1,729,292	$ 7,087,768	$ 4,177,048	$ (1,514)	$ (65,059)	$ 4,387,825	$ (900)	$ 60,352	$ 2,535,765	$ 1,791,392	$ (900)	$ 316
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,212,686				1,212,686			457,934				457,934
Dividends on Preferred Stock	(7,519)				(7,519)			(5,559)				(5,559)
Dividends on Common Stock	(767,500)				(767,500)			(69,500)				(69,500)
Capital Contributions from Eversource Parent								275,000			275,000
Other Comprehensive Income/(Loss), Net of Tax	(11,352)						(11,352)	(14)						(14)
Ending balance (in shares) at Dec. 31, 2020			342,954,023							6,035,205
Ending balance at Dec. 31, 2020	14,063,566		$ 1,789,092	8,015,663	4,613,201		(76,411)	5,044,786		$ 60,352	2,810,765	2,173,367		302
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,228,046				1,228,046			401,725				401,725
Dividends on Preferred Stock	(7,519)				(7,519)			(5,559)				(5,559)
Dividends on Common Stock	(828,337)				(828,337)			(341,400)				(341,400)
Capital Contributions from Eversource Parent	160,000							200,000			200,000
Other Comprehensive Income/(Loss), Net of Tax	$ 34,136						34,136	(51)						(51)
Ending balance (in shares) at Dec. 31, 2021	344,403,196		344,403,196							6,035,205
Ending balance at Dec. 31, 2021	$ 14,599,844		$ 1,789,092	8,098,514	5,005,391		(42,275)	5,299,501		$ 60,352	3,010,765	2,228,133		251
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,412,394				1,412,394			532,920				532,920
Dividends on Preferred Stock	(7,519)				(7,519)			(5,559)				(5,559)
Dividends on Common Stock	(883,113)				(883,113)			(292,400)				(292,400)
Capital Contributions from Eversource Parent								250,000			250,000
Other Comprehensive Income/(Loss), Net of Tax	$ 2,854						2,854	(82)						(82)
Ending balance (in shares) at Dec. 31, 2022	348,443,855		348,443,855							6,035,205
Ending balance at Dec. 31, 2022	$ 15,473,158		$ 1,799,920	$ 8,401,731	$ 5,527,153		$ (39,421)	$ 5,784,380		$ 60,352	$ 3,260,765	$ 2,463,094		$ 169

THE CONNECTICUT LIGHT AND POW_5

THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Depreciation	1,194,246	1,103,008	981,380
Deferred Income Taxes	346,779	347,056	257,154
Uncollectible Expense	61,876	60,886	53,461
Pension, SERP and PBOP (Income)/Expense, Net	(160,857)	(14,693)	12,888
Pension Contributions	(83,148)	(182,344)	(111,524)
Regulatory Under Recoveries, Net	(205,294)	(314,211)	(516,411)
(Customer Credits)/Reserve at CL&P related to PURA Settlement Agreement and Storm Performance Penalty	(72,041)	81,274	0
Cost of Removal Expenditures	(303,755)	(242,130)	(148,332)
Other	(39,192)	(64,640)	(25,957)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(470,593)	(135,505)	(351,843)
Taxes Receivable/Accrued, Net	18,358	(110,621)	43,819
Accounts Payable	377,657	(29,201)	122,567
Other Current Assets and Liabilities, Net	(45,583)	3,710	(24,995)
Net Cash Flows Provided by Operating Activities	2,401,293	1,962,600	1,682,572
Investing Activities:
Investments in Property, Plant and Equipment	(3,441,852)	(3,175,080)	(2,942,996)
Other Investing Activities	20,420	22,178	23,809
Net Cash Flows Used in Investing Activities	(4,130,490)	(3,447,374)	(4,129,275)
Financing Activities:
Cash Dividends on Common Shares	(860,033)	(805,439)	(744,665)
Cash Dividends on Preferred Stock	(7,519)	(7,519)	(7,519)
Proceeds from (Repayments of) Short-Term Debt	(78,170)	256,125	13,955
Issuance of Long-Term Debt	4,045,000	3,230,000	2,760,000
Retirement of Long-Term Debt	(1,175,000)	(1,142,500)	(327,236)
Other Financing Activities	(48,185)	(46,625)	14,273
Net Cash Flows Provided by Financing Activities	2,029,941	1,440,832	2,594,590
Net Increase/(Decrease) in Cash, Cash Equivalents and Restricted Cash	300,744	(43,942)	147,887
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	221,008	264,950	117,063
Cash, Cash Equivalents and Restricted Cash - End of Year	521,752	221,008	264,950
The Connecticut Light and Power Company
Operating Activities:
Net Income	532,920	401,725	457,934
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Depreciation	355,511	338,915	320,709
Deferred Income Taxes	45,381	123,889	144,527
Uncollectible Expense	15,578	13,495	12,882
Pension, SERP and PBOP (Income)/Expense, Net	(28,971)	5,295	11,372
Pension Contributions	0	(98,913)	(23,200)
Regulatory Under Recoveries, Net	(144,793)	(152,775)	(279,941)
(Customer Credits)/Reserve at CL&P related to PURA Settlement Agreement and Storm Performance Penalty	(72,041)	81,274	0
Amortization of Regulatory Assets, Net	335,636	99,009	58,412
Cost of Removal Expenditures	(71,596)	(95,792)	(57,343)
Other	(25,927)	(10,194)	(57,870)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(256,338)	(75,881)	(126,638)
Taxes Receivable/Accrued, Net	897	(25,162)	(12,014)
Accounts Payable	207,698	24,895	(17,028)
Other Current Assets and Liabilities, Net	(24,308)	(16,925)	(34,729)
Net Cash Flows Provided by Operating Activities	869,647	612,855	397,073
Investing Activities:
Investments in Property, Plant and Equipment	(876,740)	(790,083)	(833,973)
Other Investing Activities	591	329	573
Net Cash Flows Used in Investing Activities	(876,149)	(789,754)	(833,400)
Financing Activities:
Cash Dividends on Common Shares	(292,400)	(341,400)	(69,500)
Cash Dividends on Preferred Stock	(5,559)	(5,559)	(5,559)
Proceeds from (Repayments of) Short-Term Debt	0	0	(63,800)
Issuance of Long-Term Debt	0	425,000	400,000
Retirement of Long-Term Debt	0	(120,500)	0
Capital Contributions from Eversource Parent	250,000	200,000	275,000
Other Financing Activities	0	(5,663)	(4,976)
Net Cash Flows Provided by Financing Activities	(47,959)	151,878	531,165
Net Increase/(Decrease) in Cash, Cash Equivalents and Restricted Cash	(54,461)	(25,021)	94,838
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	74,788	99,809	4,971
Cash, Cash Equivalents and Restricted Cash - End of Year	$ 20,327	$ 74,788	$ 99,809

NSTAR ELECTRIC COMPANY AND SUBS

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current Assets:
Cash	$ 47,597	$ 66,773
Cash Equivalents	327,006	0
Receivables, Net (net of allowance for uncollectible accounts)	1,517,138	1,226,069
Unbilled Revenues	238,968	210,879
Materials, Supplies, Natural Gas and REC Inventory	374,395	267,547
Regulatory Assets	1,335,491	1,129,093
Prepayments and Other Current Assets	382,603	369,759
Total Current Assets	4,223,198	3,270,120
Property, Plant and Equipment, Net	36,112,820	33,377,650
Deferred Debits and Other Assets:
Regulatory Assets	4,242,794	4,586,709
Prepaid Pension and PBOP	1,045,524	271,987
Other Long-Term Assets	541,344	611,769
Total Deferred Debits and Other Assets	12,894,882	11,844,374
Total Assets	53,230,900	48,492,144
Current Liabilities:
Notes Payable	1,442,200	1,505,450
Long-Term Debt – Current Portion	1,320,129	1,193,097
Accounts Payable	2,113,905	1,672,230
Regulatory Liabilities	890,786	602,432
Other Current Liabilities	989,053	830,620
Total Current Liabilities	6,799,283	5,847,039
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	5,067,902	4,597,120
Regulatory Liabilities	3,930,305	3,866,251
Accrued Pension, SERP and PBOP	135,473	242,463
Other Long-Term Liabilities	888,081	971,080
Total Deferred Credits and Other Liabilities	10,668,403	10,412,412
Capitalization:
Long-Term Debt	19,723,994	17,023,577
Preferred Stock Not Subject to Mandatory Redemption	155,570	155,570
Common Shareholders' Equity:
Capital Surplus, Paid In	8,401,731	8,098,514
Retained Earnings	5,527,153	5,005,391
Accumulated Other Comprehensive Income/(Loss)	(39,421)	(42,275)
Common Shareholders' Equity	15,473,158	14,599,844
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	53,230,900	48,492,144
NSTAR Electric Company
Current Assets:
Cash	738	745
Cash Equivalents	327,006	0
Receivables, Net (net of allowance for uncollectible accounts)	453,371	405,674
Accounts Receivable from Affiliated Companies	35,196	67,420
Unbilled Revenues	39,680	37,497
Materials, Supplies, Natural Gas and REC Inventory	138,352	116,712
Taxes Receivable	45,474	80,617
Regulatory Assets	492,759	443,956
Prepayments and Other Current Assets	25,802	22,397
Total Current Assets	1,558,378	1,175,018
Property, Plant and Equipment, Net	11,626,968	10,876,614
Deferred Debits and Other Assets:
Regulatory Assets	1,221,619	1,135,231
Prepaid Pension and PBOP	576,809	441,426
Other Long-Term Assets	111,846	171,657
Total Deferred Debits and Other Assets	1,910,274	1,748,314
Total Assets	15,095,620	13,799,946
Current Liabilities:
Notes Payable	0	162,500
Long-Term Debt – Current Portion	80,000	400,000
Accounts Payable	559,676	490,915
Accounts Payable to Affiliated Companies	108,907	129,575
Obligations to Third Party Suppliers	142,628	116,273
Renewable Portfolio Standards Compliance Obligations	120,239	100,200
Regulatory Liabilities	373,221	228,248
Other Current Liabilities	83,925	84,303
Total Current Liabilities	1,468,596	1,712,014
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	1,700,875	1,579,508
Regulatory Liabilities	1,548,081	1,559,072
Accrued Pension, SERP and PBOP	1,619	2,046
Other Long-Term Liabilities	287,694	345,888
Total Deferred Credits and Other Liabilities	3,538,269	3,486,514
Capitalization:
Long-Term Debt	4,345,085	3,585,399
Preferred Stock Not Subject to Mandatory Redemption	43,000	43,000
Common Shareholders' Equity:
Common Shares	0	0
Capital Surplus, Paid In	2,778,942	2,253,942
Retained Earnings	2,921,444	2,718,576
Accumulated Other Comprehensive Income/(Loss)	284	501
Common Shareholders' Equity	5,700,670	4,973,019
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	$ 15,095,620	$ 13,799,946

NSTAR ELECTRIC COMPANY AND SU_2

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for uncollectible accounts	$ 486,297	$ 417,406	$ 358,900	$ 224,800
NSTAR Electric
Allowance for uncollectible accounts	$ 94,958	$ 97,005	$ 91,600	$ 75,400

NSTAR ELECTRIC COMPANY AND SU_3

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Revenues	$ 12,289,336	$ 9,863,085	$ 8,904,430
Operating Expenses:
Purchased Power and Transmission	5,014,074	3,372,344	2,987,840
Operations and Maintenance	1,865,328	1,739,685	1,480,252
Depreciation	1,194,246	1,103,008	981,380
Energy Efficiency Programs	658,051	592,775	535,760
Taxes Other Than Income Taxes	910,591	829,987	752,785
Total Operating Expenses	10,091,182	7,869,764	6,915,696
Operating Income	2,198,154	1,993,321	1,988,734
Interest Expense	678,274	582,334	538,452
Other Income, Net	346,088	161,282	108,590
Income Before Income Tax Expense	1,865,968	1,572,269	1,558,872
Income Tax Expense	453,574	344,223	346,186
Net Income	1,412,394	1,228,046	1,212,686
NSTAR Electric Company
Operating Revenues	3,583,070	3,056,350	2,941,148
Operating Expenses:
Purchased Power and Transmission	1,264,824	932,530	879,244
Operations and Maintenance	640,834	563,172	534,118
Depreciation	361,969	337,451	319,468
Amortization of Regulatory Assets, Net	83,855	55,774	83,248
Energy Efficiency Programs	332,247	288,612	263,986
Taxes Other Than Income Taxes	246,705	216,703	206,764
Total Operating Expenses	2,930,434	2,394,242	2,286,828
Operating Income	652,636	662,108	654,320
Interest Expense	162,892	146,048	130,508
Other Income, Net	142,661	74,844	52,017
Income Before Income Tax Expense	632,405	590,904	575,829
Income Tax Expense	139,977	114,335	130,828
Net Income	$ 492,428	$ 476,569	$ 445,001

NSTAR ELECTRIC COMPANY AND SU_4

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Other Comprehensive Income/(Loss), Net of Tax:
Changes in Funded Status of SERP Benefit Plan	4,470	33,835	(13,290)
Qualified Cash Flow Hedging Instruments	20	972	1,596
Changes in Unrealized (Losses)/Gains on Marketable Securities	(1,636)	(671)	342
Other Comprehensive Income/(Loss), Net of Tax	2,854	34,136	(11,352)
Comprehensive Income Attributable to Common Shareholders	1,407,729	1,254,663	1,193,815
NSTAR Electric Company
Net Income	492,428	476,569	445,001
Other Comprehensive Income/(Loss), Net of Tax:
Changes in Funded Status of SERP Benefit Plan	(221)	(100)	(286)
Qualified Cash Flow Hedging Instruments	20	298	437
Changes in Unrealized (Losses)/Gains on Marketable Securities	(16)	(6)	3
Other Comprehensive Income/(Loss), Net of Tax	(217)	192	154
Comprehensive Income Attributable to Common Shareholders	$ 492,211	$ 476,761	$ 445,155

NSTAR ELECTRIC COMPANY AND SU_5

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Thousands	Total	Adoption of New Accounting Standard	Common Stock	Capital Surplus, Paid In	Retained Earnings	Retained Earnings Adoption of New Accounting Standard	Accumulated Other Comprehensive Income (Loss)	NSTAR Electric	NSTAR Electric Adoption of New Accounting Standard	NSTAR Electric Common Stock	NSTAR Electric Capital Surplus, Paid In	NSTAR Electric Retained Earnings	NSTAR Electric Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2019			329,880,645							200
Beginning balance at Dec. 31, 2019	$ 12,629,994	$ (1,514)	$ 1,729,292	$ 7,087,768	$ 4,177,048	$ (1,514)	$ (65,059)	$ 4,159,884	$ (161)	$ 0	$ 1,813,442	$ 2,346,287	$ 155
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,212,686				1,212,686			445,001				445,001
Dividends on Preferred Stock	(7,519)				(7,519)			(1,960)				(1,960)
Dividends on Common Stock	(767,500)				(767,500)			(262,000)				(262,000)
Capital Contributions from Eversource Parent								180,500			180,500
Other Comprehensive Income/(Loss), Net of Tax	(11,352)						(11,352)	154					154
Ending balance (in shares) at Dec. 31, 2020			342,954,023							200
Ending balance at Dec. 31, 2020	14,063,566		$ 1,789,092	8,015,663	4,613,201		(76,411)	4,521,418		$ 0	1,993,942	2,527,167	309
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,228,046				1,228,046			476,569				476,569
Dividends on Preferred Stock	(7,519)				(7,519)			(1,960)				(1,960)
Dividends on Common Stock	(828,337)				(828,337)			(283,200)				(283,200)
Capital Contributions from Eversource Parent	160,000							260,000			260,000
Other Comprehensive Income/(Loss), Net of Tax	$ 34,136						34,136	192					192
Ending balance (in shares) at Dec. 31, 2021	344,403,196		344,403,196							200
Ending balance at Dec. 31, 2021	$ 14,599,844		$ 1,789,092	8,098,514	5,005,391		(42,275)	4,973,019		$ 0	2,253,942	2,718,576	501
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,412,394				1,412,394			492,428				492,428
Dividends on Preferred Stock	(7,519)				(7,519)			(1,960)				(1,960)
Dividends on Common Stock	(883,113)				(883,113)			(287,600)				(287,600)
Capital Contributions from Eversource Parent								525,000			525,000
Other Comprehensive Income/(Loss), Net of Tax	$ 2,854						2,854	(217)					(217)
Ending balance (in shares) at Dec. 31, 2022	348,443,855		348,443,855							200
Ending balance at Dec. 31, 2022	$ 15,473,158		$ 1,799,920	$ 8,401,731	$ 5,527,153		$ (39,421)	$ 5,700,670		$ 0	$ 2,778,942	$ 2,921,444	$ 284

NSTAR ELECTRIC COMPANY AND SU_6

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Depreciation	1,194,246	1,103,008	981,380
Deferred Income Taxes	346,779	347,056	257,154
Pension, SERP and PBOP (Income)/Expense, Net	(160,857)	(14,693)	12,888
Pension Contributions	(83,148)	(182,344)	(111,524)
Regulatory Under Recoveries, Net	(205,294)	(314,211)	(516,411)
Uncollectible Expense	61,876	60,886	53,461
Cost of Removal Expenditures	(303,755)	(242,130)	(148,332)
Payment of Withheld Property Taxes	(78,446)	0	0
Other	(39,192)	(64,640)	(25,957)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(470,593)	(135,505)	(351,843)
Taxes Receivable/Accrued, Net	18,358	(110,621)	43,819
Accounts Payable	377,657	(29,201)	122,567
Other Current Assets and Liabilities, Net	(45,583)	3,710	(24,995)
Net Cash Flows Provided by Operating Activities	2,401,293	1,962,600	1,682,572
Investing Activities:
Investments in Property, Plant and Equipment	(3,441,852)	(3,175,080)	(2,942,996)
Other Investing Activities	20,420	22,178	23,809
Net Cash Flows Used in Investing Activities	(4,130,490)	(3,447,374)	(4,129,275)
Financing Activities:
Cash Dividends on Common Shares	(860,033)	(805,439)	(744,665)
Cash Dividends on Preferred Stock	(7,519)	(7,519)	(7,519)
Proceeds from (Repayments of) Short-Term Debt	(78,170)	256,125	13,955
Issuance of Long-Term Debt	4,045,000	3,230,000	2,760,000
Retirement of Long-Term Debt	(1,175,000)	(1,142,500)	(327,236)
Other Financing Activities	(48,185)	(46,625)	14,273
Net Cash Flows Provided by Financing Activities	2,029,941	1,440,832	2,594,590
Net Increase/(Decrease) in Cash, Cash Equivalents and Restricted Cash	300,744	(43,942)	147,887
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	221,008	264,950	117,063
Cash, Cash Equivalents and Restricted Cash - End of Year	521,752	221,008	264,950
NSTAR Electric
Operating Activities:
Net Income	492,428	476,569	445,001
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Depreciation	361,969	337,451	319,468
Deferred Income Taxes	78,039	57,507	72,595
Pension, SERP and PBOP (Income)/Expense, Net	(55,830)	(26,120)	(18,132)
Pension Contributions	(15,000)	(30,000)	(650)
Regulatory Under Recoveries, Net	(88,220)	(79,075)	(186,081)
Amortization of Regulatory Assets, Net	83,855	55,774	83,248
Uncollectible Expense	21,550	16,649	15,293
Cost of Removal Expenditures	(57,339)	(58,967)	(39,166)
Payment of Withheld Property Taxes	(76,311)	0	0
Other	(14,294)	(32,447)	(22,888)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(23,757)	(45,774)	(81,571)
Taxes Receivable/Accrued, Net	35,143	(16,219)	(44,045)
Accounts Payable	8,815	31,650	25,573
Other Current Assets and Liabilities, Net	20,430	13,944	(42,831)
Net Cash Flows Provided by Operating Activities	771,478	700,942	525,814
Investing Activities:
Investments in Property, Plant and Equipment	(954,281)	(960,949)	(907,000)
Other Investing Activities	165	91	159
Net Cash Flows Used in Investing Activities	(954,116)	(960,858)	(906,841)
Financing Activities:
Cash Dividends on Common Shares	(287,600)	(283,200)	(262,000)
Cash Dividends on Preferred Stock	(1,960)	(1,960)	(1,960)
(Decrease)/Increase in Notes Payable	(162,500)	(32,500)	184,500
Proceeds from (Repayments of) Short-Term Debt	0	(21,300)	(9,000)
Capital Contributions from Eversource Parent	525,000	260,000	180,500
Issuance of Long-Term Debt	850,000	600,000	400,000
Retirement of Long-Term Debt	(400,000)	(250,000)	(95,000)
Other Financing Activities	(13,188)	(10,355)	(4,915)
Net Cash Flows Provided by Financing Activities	509,752	260,685	392,125
Net Increase/(Decrease) in Cash, Cash Equivalents and Restricted Cash	327,114	769	11,098
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	18,179	17,410	6,312
Cash, Cash Equivalents and Restricted Cash - End of Year	$ 345,293	$ 18,179	$ 17,410

PUBLIC SERVICE COMPANY OF NEW H

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current Assets:
Cash	$ 47,597	$ 66,773
Receivables, Net (net of allowance for uncollectible accounts)	1,517,138	1,226,069
Unbilled Revenues	238,968	210,879
Materials, Supplies and REC Inventory	374,395	267,547
Regulatory Assets	1,335,491	1,129,093
Prepayments and Other Current Assets	382,603	369,759
Total Current Assets	4,223,198	3,270,120
Property, Plant and Equipment, Net	36,112,820	33,377,650
Deferred Debits and Other Assets:
Regulatory Assets	4,242,794	4,586,709
Prepaid Pension	1,045,524	271,987
Other Long-Term Assets	541,344	611,769
Total Deferred Debits and Other Assets	12,894,882	11,844,374
Total Assets	53,230,900	48,492,144
Current Liabilities:
Long-Term Debt – Current Portion	1,320,129	1,193,097
Rate Reduction Bonds – Current Portion	43,210	43,210
Accounts Payable	2,113,905	1,672,230
Regulatory Liabilities	890,786	602,432
Other Current Liabilities	989,053	830,620
Total Current Liabilities	6,799,283	5,847,039
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	5,067,902	4,597,120
Regulatory Liabilities	3,930,305	3,866,251
Accrued Pension, SERP and PBOP	135,473	242,463
Other Long-Term Liabilities	888,081	971,080
Total Deferred Credits and Other Liabilities	10,668,403	10,412,412
Capitalization:
Long-Term Debt	19,723,994	17,023,577
Rate Reduction Bonds	410,492	453,702
Common Shareholders' Equity:
Capital Surplus, Paid In	8,401,731	8,098,514
Retained Earnings	5,527,153	5,005,391
Accumulated Other Comprehensive Income/(Loss)	(39,421)	(42,275)
Common Shareholders' Equity	15,473,158	14,599,844
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	53,230,900	48,492,144
PSNH
Current Assets:
Cash	136	15
Receivables, Net (net of allowance for uncollectible accounts)	173,337	124,232
Accounts Receivable from Affiliated Companies	8,193	17,156
Unbilled Revenues	72,713	53,937
Taxes Receivable	27,978	4,487
Materials, Supplies and REC Inventory	34,521	25,930
Regulatory Assets	102,240	107,169
Special Deposits	33,140	31,390
Prepayments and Other Current Assets	13,297	17,622
Total Current Assets	465,555	381,938
Property, Plant and Equipment, Net	4,060,224	3,656,462
Deferred Debits and Other Assets:
Regulatory Assets	593,974	679,182
Prepaid Pension	66,384	0
Other Long-Term Assets	16,517	23,202
Total Deferred Debits and Other Assets	676,875	702,384
Total Assets	5,202,654	4,740,784
Current Liabilities:
Notes Payable to Eversource Parent	173,300	110,600
Long-Term Debt – Current Portion	29,668	0
Rate Reduction Bonds – Current Portion	43,210	43,210
Accounts Payable	291,556	166,452
Accounts Payable to Affiliated Companies	36,231	43,485
Regulatory Liabilities	161,963	120,176
Other Current Liabilities	59,616	63,005
Total Current Liabilities	795,544	546,928
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	562,802	537,978
Regulatory Liabilities	391,628	381,366
Accrued Pension, SERP and PBOP	6,508	30,184
Other Long-Term Liabilities	30,579	34,080
Total Deferred Credits and Other Liabilities	991,517	983,608
Capitalization:
Long-Term Debt	1,134,914	1,163,833
Rate Reduction Bonds	410,492	453,702
Common Shareholders' Equity:
Common Shares	0	0
Capital Surplus, Paid In	1,298,134	1,088,134
Retained Earnings	572,126	504,556
Accumulated Other Comprehensive Income/(Loss)	(73)	23
Common Shareholders' Equity	1,870,187	1,592,713
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	$ 5,202,654	$ 4,740,784

PUBLIC SERVICE COMPANY OF NEW_2

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for uncollectible accounts	$ 486,297	$ 417,406	$ 358,900	$ 224,800
PSNH
Allowance for uncollectible accounts	$ 29,236	$ 24,331	$ 17,200	$ 10,500

PUBLIC SERVICE COMPANY OF NEW_3

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Revenues	$ 12,289,336	$ 9,863,085	$ 8,904,430
Operating Expenses:
Purchased Power and Transmission	5,014,074	3,372,344	2,987,840
Operations and Maintenance	1,865,328	1,739,685	1,480,252
Depreciation	1,194,246	1,103,008	981,380
Energy Efficiency Programs	658,051	592,775	535,760
Taxes Other Than Income Taxes	910,591	829,987	752,785
Total Operating Expenses	10,091,182	7,869,764	6,915,696
Operating Income	2,198,154	1,993,321	1,988,734
Interest Expense	678,274	582,334	538,452
Other Income, Net	346,088	161,282	108,590
Income Before Income Tax Expense	1,865,968	1,572,269	1,558,872
Income Tax Expense	453,574	344,223	346,186
Net Income	1,412,394	1,228,046	1,212,686
PSNH
Operating Revenues	1,474,799	1,177,248	1,079,095
Operating Expenses:
Purchased Power and Transmission	665,478	370,271	364,067
Operations and Maintenance	255,991	237,659	219,325
Depreciation	127,962	120,065	100,372
Amortization of Regulatory Assets, Net	42,867	86,832	52,804
Energy Efficiency Programs	37,434	38,752	37,583
Taxes Other Than Income Taxes	95,301	91,465	81,611
Total Operating Expenses	1,225,033	945,044	855,762
Operating Income	249,766	232,204	223,333
Interest Expense	59,548	56,998	58,127
Other Income, Net	32,666	14,565	13,786
Income Before Income Tax Expense	222,884	189,771	178,992
Income Tax Expense	51,314	39,433	31,680
Net Income	$ 171,570	$ 150,338	$ 147,312

PUBLIC SERVICE COMPANY OF NEW_4

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	20	972	1,596
Changes in Unrealized (Losses)/Gains on Marketable Securities	(1,636)	(671)	342
Other Comprehensive Income/(Loss), Net of Tax	2,854	34,136	(11,352)
Comprehensive Income Attributable to Common Shareholders	1,407,729	1,254,663	1,193,815
PSNH
Net Income	171,570	150,338	147,312
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	0	673	1,075
Changes in Unrealized (Losses)/Gains on Marketable Securities	(96)	(37)	19
Other Comprehensive Income/(Loss), Net of Tax	(96)	636	1,094
Comprehensive Income Attributable to Common Shareholders	$ 171,474	$ 150,974	$ 148,406

PUBLIC SERVICE COMPANY OF NEW_5

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Thousands	Total	Adoption of New Accounting Standard	Common Stock	Capital Surplus, Paid In	Retained Earnings	Retained Earnings Adoption of New Accounting Standard	Accumulated Other Comprehensive Income (Loss)	PSNH	PSNH Adoption of New Accounting Standard	PSNH Common Stock	PSNH Capital Surplus, Paid In	PSNH Retained Earnings	PSNH Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2019			329,880,645							301
Beginning balance at Dec. 31, 2019	$ 12,629,994	$ (1,514)	$ 1,729,292	$ 7,087,768	$ 4,177,048	$ (1,514)	$ (65,059)	$ 1,391,733	$ (300)	$ 0	$ 903,134	$ 490,306	$ (1,707)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,212,686				1,212,686			147,312				147,312
Dividends on Common Stock	(767,500)				(767,500)			(22,300)				(22,300)
Capital Contributions from Eversource Parent								25,000			25,000
Other Comprehensive Income/(Loss), Net of Tax	(11,352)						(11,352)	1,094					1,094
Ending balance (in shares) at Dec. 31, 2020			342,954,023							301
Ending balance at Dec. 31, 2020	14,063,566		$ 1,789,092	8,015,663	4,613,201		(76,411)	1,542,539		$ 0	928,134	615,018	(613)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,228,046				1,228,046			150,338				150,338
Dividends on Common Stock	(828,337)				(828,337)			(260,800)				(260,800)
Capital Contributions from Eversource Parent	160,000										160,000
Other Comprehensive Income/(Loss), Net of Tax	$ 34,136						34,136	636					636
Ending balance (in shares) at Dec. 31, 2021	344,403,196		344,403,196							301
Ending balance at Dec. 31, 2021	$ 14,599,844		$ 1,789,092	8,098,514	5,005,391		(42,275)	1,592,713		$ 0	1,088,134	504,556	23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,412,394				1,412,394			171,570				171,570
Dividends on Common Stock	(883,113)				(883,113)			(104,000)				(104,000)
Capital Contributions from Eversource Parent								210,000			210,000
Other Comprehensive Income/(Loss), Net of Tax	$ 2,854						2,854	(96)					(96)
Ending balance (in shares) at Dec. 31, 2022	348,443,855		348,443,855							301
Ending balance at Dec. 31, 2022	$ 15,473,158		$ 1,799,920	$ 8,401,731	$ 5,527,153		$ (39,421)	$ 1,870,187		$ 0	$ 1,298,134	$ 572,126	$ (73)

PUBLIC SERVICE COMPANY OF NEW_6

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Depreciation	1,194,246	1,103,008	981,380
Deferred Income Taxes	346,779	347,056	257,154
Uncollectible Expense	61,876	60,886	53,461
Pension, SERP and PBOP Income, Net	(160,857)	(14,693)	12,888
Pension Contributions	(83,148)	(182,344)	(111,524)
Regulatory Over/(Under) Recoveries, Net	(205,294)	(314,211)	(516,411)
Cost of Removal Expenditures	(303,755)	(242,130)	(148,332)
Other	(39,192)	(64,640)	(25,957)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(470,593)	(135,505)	(351,843)
Taxes Receivable/Accrued, Net	18,358	(110,621)	43,819
Accounts Payable	377,657	(29,201)	122,567
Other Current Assets and Liabilities, Net	(45,583)	3,710	(24,995)
Net Cash Flows Provided by Operating Activities	2,401,293	1,962,600	1,682,572
Investing Activities:
Investments in Property, Plant and Equipment	(3,441,852)	(3,175,080)	(2,942,996)
Other Investing Activities	20,420	22,178	23,809
Net Cash Flows Used in Investing Activities	(4,130,490)	(3,447,374)	(4,129,275)
Financing Activities:
Cash Dividends on Common Shares	(860,033)	(805,439)	(744,665)
Increase (Decrease) in Notes Payable to Eversource Parent	78,170	(256,125)	(13,955)
Issuance of Long-Term Debt	4,045,000	3,230,000	2,760,000
Retirement of Long-Term Debt	(1,175,000)	(1,142,500)	(327,236)
Repayment of Rate Reduction Bonds	(43,210)	(43,210)	(43,210)
Other Financing Activities	(48,185)	(46,625)	14,273
Net Cash Flows Provided by Financing Activities	2,029,941	1,440,832	2,594,590
Net Increase/(Decrease) in Cash, Cash Equivalents and Restricted Cash	300,744	(43,942)	147,887
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	221,008	264,950	117,063
Cash, Cash Equivalents and Restricted Cash - End of Year	521,752	221,008	264,950
PSNH
Operating Activities:
Net Income	171,570	150,338	147,312
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Depreciation	127,962	120,065	100,372
Deferred Income Taxes	15,765	(14,530)	7,337
Uncollectible Expense	9,211	13,113	5,164
Pension, SERP and PBOP Income, Net	(16,421)	(3,296)	(1,255)
Pension Contributions	0	0	(19,500)
Regulatory Over/(Under) Recoveries, Net	53,181	32,587	(45,830)
Amortization of Regulatory Assets, Net	42,867	86,832	52,804
Cost of Removal Expenditures	(39,895)	(30,804)	(22,063)
Other	8,691	(1,370)	17,221
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(62,078)	(32,003)	(33,612)
Taxes Receivable/Accrued, Net	(23,492)	3,952	(6,942)
Accounts Payable	81,046	(3,256)	27,270
Other Current Assets and Liabilities, Net	(6,908)	14,454	(9,610)
Net Cash Flows Provided by Operating Activities	361,499	336,082	218,668
Investing Activities:
Investments in Property, Plant and Equipment	(485,611)	(326,379)	(342,586)
Other Investing Activities	1,013	562	982
Net Cash Flows Used in Investing Activities	(484,598)	(325,817)	(341,604)
Financing Activities:
Cash Dividends on Common Shares	(104,000)	(260,800)	(22,300)
Increase (Decrease) in Notes Payable to Eversource Parent	62,700	64,300	19,300
Issuance of Long-Term Debt	0	350,000	150,000
Retirement of Long-Term Debt	0	(282,000)	0
Repayment of Rate Reduction Bonds	(43,210)	(43,210)	(43,210)
Capital Contributions from Eversource Parent	210,000	160,000	25,000
Other Financing Activities	(705)	(2,984)	(2,987)
Net Cash Flows Provided by Financing Activities	124,785	(14,694)	125,803
Net Increase/(Decrease) in Cash, Cash Equivalents and Restricted Cash	1,686	(4,429)	2,867
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	35,126	39,555	36,688
Cash, Cash Equivalents and Restricted Cash - End of Year	$ 36,812	$ 35,126	$ 39,555

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES A. About Eversource, CL&P, NSTAR Electric and PSNH Eversource Energy is a public utility holding company primarily engaged, through its wholly-owned regulated utility subsidiaries, in the energy delivery business. Eversource Energy's wholly-owned regulated utility subsidiaries consist of CL&P, NSTAR Electric and PSNH (electric utilities), Yankee Gas, NSTAR Gas and EGMA (natural gas utilities), and Aquarion (water utilities). Eversource provides energy delivery and/or water service to approximately 4.4 million electric, natural gas and water customers through twelve regulated utilities in Connecticut, Massachusetts and New Hampshire. Eversource, CL&P, NSTAR Electric and PSNH are reporting companies under the Securities Exchange Act of 1934. Eversource Energy is a public utility holding company under the Public Utility Holding Company Act of 2005. Arrangements among the regulated electric companies and other Eversource companies, outside agencies and other utilities covering interconnections, interchange of electric power and sales of utility property are subject to regulation by the FERC. Eversource's regulated companies are subject to regulation of rates, accounting and other matters by the FERC and/or applicable state regulatory commissions (the PURA for CL&P, Yankee Gas and Aquarion, the DPU for NSTAR Electric, NSTAR Gas, EGMA and Aquarion, and the NHPUC for PSNH and Aquarion). CL&P, NSTAR Electric and PSNH furnish franchised retail electric service in Connecticut, Massachusetts and New Hampshire, respectively. NSTAR Gas and EGMA are engaged in the distribution and sale of natural gas to customers within Massachusetts and Yankee Gas is engaged in the distribution and sale of natural gas to customers within Connecticut. Aquarion is engaged in the collection, treatment and distribution of water in Connecticut, Massachusetts and New Hampshire. CL&P, NSTAR Electric and PSNH's results include the operations of their respective distribution and transmission businesses. The distribution business also includes the results of NSTAR Electric's solar power facilities. Eversource Service, Eversource's service company, and several wholly-owned real estate subsidiaries of Eversource, provide support services to Eversource, including its regulated companies. B. Basis of Presentation The consolidated financial statements of Eversource, NSTAR Electric and PSNH include the accounts of each of their respective subsidiaries. Intercompany transactions have been eliminated in consolidation. The accompanying consolidated financial statements of Eversource, NSTAR Electric and PSNH and the financial statements of CL&P are herein collectively referred to as the "financial statements." The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. CYAPC and YAEC are inactive regional nuclear power companies engaged in the long-term storage of their spent nuclear fuel. Eversource consolidates the operations of CYAPC and YAEC because CL&P's, NSTAR Electric's and PSNH's combined ownership and voting interests in each of these entities is greater than 50 percent. Intercompany transactions between CL&P, NSTAR Electric, PSNH and the CYAPC and YAEC companies have been eliminated in consolidation of the Eversource financial statements. Eversource holds several equity ownership interests that are not consolidated and are accounted for under the equity method. In accordance with accounting guidance on noncontrolling interests in consolidated financial statements, the Preferred Stock of CL&P and the Preferred Stock of NSTAR Electric, which are not owned by Eversource or its consolidated subsidiaries and are not subject to mandatory redemption, have been presented as noncontrolling interests in the financial statements of Eversource. The Preferred Stock of CL&P and the Preferred Stock of NSTAR Electric are considered to be temporary equity and have been classified between liabilities and permanent shareholders' equity on the balance sheets of Eversource, CL&P and NSTAR Electric due to a provision in the preferred stock agreements of both CL&P and NSTAR Electric that grant preferred stockholders the right to elect a majority of the CL&P and NSTAR Electric Boards of Directors, respectively, should certain conditions exist, such as if preferred dividends are in arrears for a specified amount of time. The Net Income reported in the statements of income and cash flows represents net income prior to apportionment to noncontrolling interests, which is represented by dividends on preferred stock of CL&P and NSTAR Electric. Eversource's utility subsidiaries' electric, natural gas and water distribution and transmission businesses are subject to rate-regulation that is based on cost recovery and meets the criteria for application of accounting guidance for entities with rate-regulated operations, which considers the effect of regulation on the differences in the timing of the recognition of certain revenues and expenses from those of other businesses and industries. See Note 2, "Regulatory Accounting," for further information. As of December 31, 2022 and 2021, Eversource's carrying amount of goodwill was $4.52 billion and $4.48 billion, respectively. Eversource performs an assessment for possible impairment of its goodwill at least annually. Eversource completed its annual goodwill impairment assessment for each of its reporting units as of October 1, 2022 and determined that no impairment exists. See Note 25, "Goodwill," for further information. For the year ended December 31, 2022, no impairments to goodwill, long-lived assets, available-for-sale debt securities, or equity method investment carrying values were identified. Certain reclassifications of prior year data were made in the accompanying financial statements to conform to the current year presentation. C. Cash and Cash Equivalents Cash includes cash on hand. At the end of each reporting period, any overdraft amounts are reclassified from Cash to Accounts Payable on the balance sheets. Cash Equivalents include short-term cash investments that are highly liquid in nature and have original maturities of three months or less. D. Allowance for Uncollectible Accounts Receivables, Net on the balance sheets primarily includes trade receivables from retail customers and customers related to wholesale transmission contracts, wholesale market sales, sales of RECs, and property rentals. Receivables, Net also includes customer receivables for the purchase of electricity from a competitive third party supplier, the current portion of customer energy efficiency loans, property damage receivables and other miscellaneous receivables. There is no material concentration of receivables. Receivables are recorded at amortized cost, net of a credit loss provision (or allowance for uncollectible accounts). The current expected credit loss (CECL) model, which was implemented on January 1, 2020 (ASU 2016-13), is applied to receivables for purposes of calculating the allowance for uncollectible accounts. This model is based on expected losses and results in the recognition of estimated expected credit losses, including uncollectible amounts for both billed and unbilled revenues, over the life of the receivable at the time a receivable is recorded. The allowance for uncollectible accounts is determined based upon a variety of judgments and factors, including an aging-based quantitative assessment that applies an estimated uncollectible percentage to each receivable aging category. Factors in determining credit loss include historical collection, write-off experience, analysis of delinquency statistics, and management's assessment of collectability from customers, including current economic conditions, customer payment trends, the impact on customer bills because of energy usage trends and changes in rates, flexible payment plans and financial hardship arrearage management programs being offered to customers, reasonable forecasts, and expectations of future collectability and collection efforts. Management continuously assesses the collectability of receivables and adjusts estimates based on actual experience and future expectations based on economic conditions, collection efforts and other factors. Management also monitors the aging analysis of receivables to determine if there are changes in the collections of accounts receivable. Receivable balances are written off against the allowance for uncollectible accounts when the customer accounts are no longer in service and these balances are deemed to be uncollectible. Management concluded that the reserve balance as of December 31, 2022 adequately reflected the collection risk and net realizable value for its receivables. As of December 31, 2022 and 2021, the total amount incurred as a result of COVID-19 included in the allowance for uncollectible accounts was $50.9 million and $55.3 million at Eversource, $16.0 million and $23.9 million at CL&P, and $4.1 million and $9.0 million at NSTAR Electric, respectively. At our Connecticut and Massachusetts utilities, the COVID-19 related uncollectible amounts were deferred either as incremental regulatory costs or deferred through existing regulatory tracking mechanisms that recover uncollectible energy supply costs, as management believes it is probable that these costs will ultimately be recovered from customers in future rates. No COVID-19 related uncollectible amounts were deferred at PSNH as a result of a July 2021 NHPUC order. Based on the status of our COVID-19 regulatory dockets, policies and practices in the jurisdictions in which we operate, we believe the state regulatory commissions in Connecticut and Massachusetts will allow us to recover our incremental uncollectible customer receivable costs associated with COVID-19. The PURA allows CL&P and Yankee Gas to accelerate the recovery of accounts receivable balances attributable to qualified customers under financial or medical duress (uncollectible hardship accounts receivable) outstanding for greater than 180 days and 90 days, respectively. The DPU allows NSTAR Electric, NSTAR Gas and EGMA to recover in rates amounts associated with certain uncollectible hardship accounts receivable. These uncollectible hardship customer account balances are included in Regulatory Assets or Other Long-Term Assets on the balance sheets. Hardship customers are protected from shut-off in certain circumstances, and historical collection experience has reflected a higher default risk as compared to the rest of the receivable population. Management uses a higher credit risk profile for this pool of trade receivables as compared to non-hardship receivables. The allowance for uncollectible hardship accounts is included in the total uncollectible allowance balance. The total allowance for uncollectible accounts is included in Receivables, Net on the balance sheets. The activity in the allowance for uncollectible accounts by portfolio segment is as follows: Eversource CL&P NSTAR Electric PSNH (Millions of Dollars) Hardship Accounts Retail (Non-Hardship), Total Allowance Hardship Accounts Retail (Non-Hardship), Total Allowance Hardship Accounts Retail (Non-Hardship), Total Allowance Total Allowance Balance as of January 1, 2020 $ 143.3 $ 81.5 $ 224.8 $ 80.1 $ 17.2 $ 97.3 $ 43.9 $ 31.5 $ 75.4 $ 10.5 ASU 2016-13 Implementation 21.6 2.2 23.8 21.3 0.9 22.2 (1.6) 0.3 (1.3) 0.3 Increase due to CMA acquisition — 24.2 24.2 — — — — — — — Uncollectible Expense — 53.5 53.5 — 12.9 12.9 — 15.3 15.3 5.2 Uncollectible Costs Deferred (1) 43.1 53.9 97.0 38.2 10.8 49.0 (1.7) 26.4 24.7 7.4 Write-Offs (14.7) (63.3) (78.0) (11.9) (17.8) (29.7) (0.9) (26.3) (27.2) (6.9) Recoveries Collected 1.5 12.1 13.6 1.4 4.3 5.7 — 4.7 4.7 0.7 Balance as of December 31, 2020 $ 194.8 $ 164.1 $ 358.9 $ 129.1 $ 28.3 $ 157.4 $ 39.7 $ 51.9 $ 91.6 $ 17.2 Uncollectible Expense — 60.9 60.9 — 13.5 13.5 — 16.6 16.6 13.1 Uncollectible Costs Deferred (1) 51.9 58.7 110.6 32.3 25.5 57.8 4.3 15.8 20.1 3.1 Write-Offs (22.0) (107.7) (129.7) (18.0) (36.2) (54.2) (0.7) (36.3) (37.0) (10.0) Recoveries Collected 1.4 15.3 16.7 1.2 5.6 6.8 — 5.7 5.7 0.9 Balance as of December 31, 2021 $ 226.1 $ 191.3 $ 417.4 $ 144.6 $ 36.7 $ 181.3 $ 43.3 $ 53.7 $ 97.0 $ 24.3 Uncollectible Expense — 61.9 61.9 — 15.6 15.6 — 21.6 21.6 9.2 Uncollectible Costs Deferred (1) 77.8 34.7 112.5 58.3 1.2 59.5 1.5 10.9 12.4 2.5 Write-Offs (21.3) (102.7) (124.0) (15.3) (23.0) (38.3) (1.1) (41.2) (42.3) (7.7) Recoveries Collected 1.8 16.7 18.5 1.3 5.9 7.2 — 6.3 6.3 0.9 Balance as of December 31, 2022 $ 284.4 $ 201.9 $ 486.3 $ 188.9 $ 36.4 $ 225.3 $ 43.7 $ 51.3 $ 95.0 $ 29.2 (1) These expected credit losses are deferred as regulatory costs on the balance sheets, as these amounts are ultimately recovered in rates. Amounts include uncollectible costs for hardship accounts and other customer receivables, including uncollectible amounts related to uncollectible energy supply costs and COVID-19. The increase in the allowance for uncollectible hardship accounts in 2022 at Eversource and CL&P primarily relates to increased customer enrollment in disconnection prevention programs in Connecticut. E. Transfer of Energy Efficiency Loans CL&P transferred a portion of its energy efficiency customer loan portfolio to outside lenders in order to make additional loans to customers. CL&P remains the servicer of the loans and will transmit customer payments to the lenders, with a maximum amount outstanding under this program of $55 million. The amounts of the loans are included in Accounts Receivable, Net and Other Long-Term Assets, and are offset by Other Current Liabilities and Other Long-Term Liabilities on CL&P’s balance sheet. The current and long-term portions totaled $9.1 million and $13.0 million, respectively, as of December 31, 2022, and $10.5 million and $8.3 million, respectively, as of December 31, 2021. F. Materials, Supplies, Natural Gas and REC Inventory Materials, Supplies, Natural Gas and REC Inventory include materials and supplies purchased primarily for construction or operation and maintenance purposes, natural gas purchased for delivery to customers, and RECs. Inventory is valued at the lower of cost or net realizable value. RECs are purchased from suppliers of renewable sources of generation and are used to meet state mandated Renewable Portfolio Standards requirements. The carrying amounts of materials and supplies, natural gas inventory, and RECs, which are included in Current Assets on the balance sheets, were as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Materials and Supplies $ 221.0 $ 88.2 $ 81.0 $ 34.4 $ 148.9 $ 60.3 $ 55.0 $ 25.2 Natural Gas 95.9 — — — 56.2 — — — RECs 57.5 — 57.4 0.1 62.4 — 61.7 0.7 Total $ 374.4 $ 88.2 $ 138.4 $ 34.5 $ 267.5 $ 60.3 $ 116.7 $ 25.9 Fair value measurement guidance is applied to derivative contracts that are not elected or designated as "normal purchases" or "normal sales" (normal) and to marketable securities held in trusts. Fair value measurement guidance is also applied to valuations of the investments used to calculate the funded status of pension and PBOP plans, the nonrecurring fair value measurements of nonfinancial assets such as goodwill, long-lived assets, equity method investments, AROs, and in the valuation of business combinations and asset acquisitions. The fair value measurement guidance was also applied in estimating the fair value of preferred stock, long-term debt and RRBs. Fair Value Hierarchy: In measuring fair value, Eversource uses observable market data when available in order to minimize the use of unobservable inputs. Inputs used in fair value measurements are categorized into three fair value hierarchy levels for disclosure purposes. The entire fair value measurement is categorized based on the lowest level of input that is significant to the fair value measurement. Eversource evaluates the classification of assets and liabilities measured at fair value on a quarterly basis. The levels of the fair value hierarchy are described below: Level 1 - Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 - Inputs are quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which all significant inputs are observable. Level 3 - Quoted market prices are not available. Fair value is derived from valuation techniques in which one or more significant inputs or assumptions are unobservable. Where possible, valuation techniques incorporate observable market inputs that can be validated to external sources such as industry exchanges, including prices of energy and energy-related products. Uncategorized - Investments that are measured at net asset value are not categorized within the fair value hierarchy. Determination of Fair Value: The valuation techniques and inputs used in Eversource's fair value measurements are described in Note 4, "Derivative Instruments," Note 5, "Marketable Securities," Note 6, "Investments in Unconsolidated Affiliates," Note 7, "Asset Retirement Obligations," Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," Note 15, "Fair Value of Financial Instruments," and Note 25, “Goodwill,” to the financial statements. H. Derivative Accounting Many of the electric and natural gas companies' contracts for the purchase and sale of energy or energy-related products are derivatives. The accounting treatment for energy contracts entered into varies and depends on the intended use of the particular contract and on whether or not the contract is a derivative. The application of derivative accounting is complex and requires management judgment in the following respects: identification of derivatives and embedded derivatives, election and designation of a contract as normal, and determination of the fair value of derivative contracts. All of these judgments can have a significant impact on the financial statements. The judgment applied in the election of a contract as normal (and resulting accrual accounting) includes the conclusion that it is probable at the inception of the contract and throughout its term that it will result in physical delivery of the underlying product and that the quantities will be used or sold by the business in the normal course of business. If facts and circumstances change and management can no longer support this conclusion, then a contract cannot be considered normal, accrual accounting is terminated, and fair value accounting is applied prospectively. The fair value of derivative contracts is based upon the contract terms and conditions and the underlying market price or fair value per unit. When quantities are not specified in the contract, the Company determines whether the contract has a determinable quantity by using amounts referenced in default provisions and other relevant sections of the contract. The fair value of derivative assets and liabilities with the same counterparty are offset and recorded as a net derivative asset or liability on the balance sheets. Regulatory assets or regulatory liabilities are recorded to offset the fair values of these derivative contracts related to energy and energy-related products, as contract settlements are recovered from, or refunded to, customers in future rates. All changes in the fair value of these derivative contracts are recorded as regulatory assets or liabilities and do not impact net income. For further information regarding derivative contracts, see Note 4, "Derivative Instruments," to the financial statements. I. Operating Expenses The cost of natural gas included in Purchased Power, Purchased Natural Gas and Transmission on the statements of income were as follows: For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Eversource - Cost of Natural Gas $ 1,010.2 $ 718.6 $ 464.2 AFUDC represents the cost of borrowed and equity funds used to finance construction and is included in the cost of the electric, natural gas and water companies' utility plant on the balance sheet. The portion of AFUDC attributable to borrowed funds is recorded as a reduction of Interest Expense, and the AFUDC related to equity funds is recorded as Other Income, Net on the statements of income. AFUDC costs are recovered from customers over the service life of the related plant in the form of increased revenue collected as a result of higher depreciation expense. The average AFUDC rate is based on a FERC-prescribed formula using the cost of a company's short-term financings and capitalization (preferred stock, long-term debt and common equity), as appropriate. The average rate is applied to average eligible CWIP amounts to calculate AFUDC. AFUDC costs and the weighted-average AFUDC rates were as follows: Eversource For the Years Ended December 31, (Millions of Dollars, except percentages) 2022 2021 2020 Borrowed Funds $ 21.8 $ 18.4 $ 23.7 Equity Funds 47.3 37.3 42.0 Total AFUDC $ 69.1 $ 55.7 $ 65.7 Average AFUDC Rate 4.7 % 4.2 % 5.0 % For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars, CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Borrowed Funds $ 4.8 $ 10.7 $ 1.4 $ 2.9 $ 9.0 $ 0.8 $ 6.6 $ 9.1 $ 2.1 Equity Funds 13.6 24.6 2.5 7.7 20.4 1.6 13.8 21.5 4.2 Total AFUDC $ 18.4 $ 35.3 $ 3.9 $ 10.6 $ 29.4 $ 2.4 $ 20.4 $ 30.6 $ 6.3 Average AFUDC Rate 6.6 % 5.4 % 2.6 % 5.0 % 4.9 % 2.5 % 5.9 % 5.7 % 4.7 % K. Other Income, Net The components of Other Income, Net on the statements of income were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion (1) $ 219.8 $ 84.4 $ 44.4 AFUDC Equity 47.3 37.3 42.0 Equity in Earnings of Unconsolidated Affiliates (2) 22.9 14.2 14.2 Investment Income/(Loss) 1.9 (0.2) 1.1 Interest Income 50.5 25.6 4.8 Gain on Sale of Property 2.6 0.1 1.8 Other 1.1 (0.1) 0.3 Total Other Income, Net $ 346.1 $ 161.3 $ 108.6 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion (1) $ 64.4 $ 85.5 $ 26.8 $ 15.2 $ 40.2 $ 10.3 $ 3.8 $ 29.3 $ 7.0 AFUDC Equity 13.6 24.6 2.5 7.7 20.4 1.6 13.8 21.5 4.2 Investment (Loss)/Income (1.3) 1.2 0.2 1.3 0.1 0.1 1.1 (0.8) 0.1 Interest Income 6.5 30.7 3.1 5.9 13.4 2.4 2.0 0.9 2.4 Other 0.1 0.7 0.1 0.1 0.7 0.2 0.1 1.1 0.1 Total Other Income, Net $ 83.3 $ 142.7 $ 32.7 $ 30.2 $ 74.8 $ 14.6 $ 20.8 $ 52.0 $ 13.8 (1) See Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," for the components of net periodic benefit income/expense for the Pension, SERP and PBOP Plans. The non-service related components of pension, SERP and PBOP benefit income/expense, after capitalization or deferral, are presented as non-operating income and recorded in Other Income, Net on the statements of income. (2) Equity in earnings of unconsolidated affiliates includes $12.2 million and $2.1 million of pre-tax unrealized gains for the years ended December 31, 2022 and 2021, respectively, and $2.4 million of primarily realized gains for the year ended December 31, 2020, associated with an equity method investment in a renewable energy fund. Equity in earnings of unconsolidated affiliates for the year ended December 31, 2020 includes an other-than-temporary impairment of $2.8 million related to a write-off of an investment within a renewable energy fund. See Note 6, "Investments in Unconsolidated Affiliates," for Eversource’s equity method investments. L. Other Taxes Eversource's companies that serve customers in Connecticut collect gross receipts taxes levied by the state of Connecticut from their customers. These gross receipts taxes are recorded separately with collections in Operating Revenues and with payments in Taxes Other Than Income Taxes on the statements of income as follows: For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Eversource $ 194.7 $ 181.9 $ 170.6 CL&P 166.1 158.1 149.9 As agents for state and local governments, Eversource's companies that serve customers in Connecticut and Massachusetts collect certain sales taxes that are recorded on a net basis with no impact on the statements of income. M. Supplemental Cash Flow Information Eversource (Millions of Dollars) As of and For the Years Ended December 31, 2022 2021 2020 Cash Paid During the Year for: Interest, Net of Amounts Capitalized $ 636.2 $ 568.7 $ 518.0 Income Taxes 77.9 121.6 48.9 Non-Cash Investing Activities: Plant Additions Included in Accounts Payable (As of) 586.9 467.9 367.2 As of and For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Cash Paid During the Year for: Interest, Net of Amounts Capitalized $ 167.2 $ 152.8 $ 58.3 $ 161.5 $ 141.6 $ 56.5 $ 149.0 $ 129.4 $ 54.5 Income Taxes 117.6 23.8 58.3 38.4 74.2 51.1 10.9 110.7 34.2 Non-Cash Investing Activities: Plant Additions Included in Accounts 131.8 184.3 76.2 110.6 120.0 68.7 101.8 103.2 33.3 The following table reconciles cash and cash equivalents as reported on the balance sheets to the cash, cash equivalents and restricted cash balance as reported on the statements of cash flows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Cash and Cash Equivalents as reported on the $ 374.6 $ 11.3 $ 327.7 $ 0.1 $ 66.8 $ 55.8 $ 0.7 $ — Restricted cash included in: Special Deposits 102.2 8.8 17.5 33.1 78.2 18.7 17.4 31.4 Marketable Securities 25.4 0.2 0.1 0.4 31.3 0.3 0.1 0.5 Other Long-Term Assets 19.6 — — 3.2 44.7 — — 3.2 Cash, Cash Equivalents and Restricted Cash $ 521.8 $ 20.3 $ 345.3 $ 36.8 $ 221.0 $ 74.8 $ 18.2 $ 35.1 Special Deposits represent cash collections related to the PSNH RRB customer charges that are held in trust, required ISO-NE cash deposits, cash held in escrow accounts, and CYAPC and YAEC cash balances. The December 31, 2021 balance also included a $10 million customer assistance fund to provide bill payment assistance to certain existing non-hardship and hardship customers carrying arrearages at CL&P established under the terms of the PURA-approved October 2021 settlement agreement. Those customers were provided with $10 million of bill forgiveness in the first quarter of 2022, which represented a non-cash transaction. Special Deposits are included in Current Assets on the balance sheets. Restricted cash included in Marketable Securities represents money market funds held in trusts to fund certain non-qualified executive benefits and restricted trusts to fund CYAPC and YAEC's spent nuclear fuel storage obligations. Restricted cash also includes an Energy Relief Fund for energy efficiency and clean energy measures in the Merrimack Valley and an additional energy efficiency program established under the terms of the EGMA 2020 settlement agreement. As of December 31, 2022, $20.0 million of this restricted cash was recorded as short-term in Special Deposits and $15.9 million was recorded in Other Long-Term Assets. As of December 31, 2021, this restricted cash totaled $41.5 million and was recorded in Other Long-Term Assets on the balance sheet. Cash Equivalents at NSTAR Electric of $327.0 million related to a cash infusion by Eversource parent received in December 2022 recorded in a money market account. N. Related Parties Eversource Service, Eversource's service company, provides centralized accounting, administrative, engineering, financial, information technology, legal, operational, planning, purchasing, tax, and other services to Eversource's companies. The Rocky River Realty Company and Properties, Inc., two other Eversource subsidiaries, construct, acquire or lease some of the property and facilities used by Eversource's companies. As of both December 31, 2022 and 2021, CL&P, NSTAR Electric and PSNH had long-term receivables from Eversource Service in the amounts of $25.0 million, $5.5 million and $3.8 million, respectively, which were included in Other Long-Term Assets on the balance sheets. These amounts related to the funding of investments held in trust by Eversource Service in connection with certain postretirement benefits for CL&P, NSTAR Electric and PSNH employees and have been eliminated in consolidation on the Eversource financial statements. Included in the CL&P, NSTAR Electric and PSNH balance sheets as of December 31, 2022 and 2021 were Accounts Receivable from Affiliated Companies and Accounts Payable to Affiliated Companies relating to transactions between CL&P, NSTAR Electric and PSNH and other subsidiaries that are wholly-owned by Eversource. These amounts have been eliminated in consolidation on the Eversource financial statements. The Eversource Energy Foundation is an independent not-for-profit charitable entity and is not included in the consolidated financial statements of Eversource as the Company does not have title to, and cannot receive contributions back from, the Eversource Energy Foundation's assets. Eversource made contributions to the Eversource Energy Foundation of $8.0 million in 2022 and $6.4 million in 2020 and did not make any contributions in 2021.

REGULATORY ACCOUNTING

REGULATORY ACCOUNTING	12 Months Ended
	Dec. 31, 2022
Regulated Operations [Abstract]
REGULATORY ACCOUNTING	REGULATORY ACCOUNTING Eversource's utility companies are subject to rate regulation that is based on cost recovery and meets the criteria for application of accounting guidance for rate-regulated operations, which considers the effect of regulation on the timing of the recognition of certain revenues and expenses. The regulated companies' financial statements reflect the effects of the rate-making process. The rates charged to the customers of Eversource's regulated companies are designed to collect each company's costs to provide service, plus a return on investment. The application of accounting guidance for rate-regulated enterprises results in recording regulatory assets and liabilities. Regulatory assets represent the deferral of incurred costs that are probable of future recovery in customer rates. Regulatory assets are amortized as the incurred costs are recovered through customer rates. Regulatory liabilities represent either revenues received from customers to fund expected costs that have not yet been incurred or probable future refunds to customers. Management believes it is probable that each of the regulated companies will recover its respective investments in long-lived assets and the regulatory assets that have been recorded. If management were to determine that it could no longer apply the accounting guidance applicable to rate-regulated enterprises, or if management could not conclude it is probable that costs would be recovered from customers in future rates, the applicable costs would be charged to net income in the period in which the determination is made. Regulatory Assets: The components of regulatory assets were as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Benefit Costs $ 921.7 $ 156.7 $ 299.5 $ 56.6 $ 1,481.0 $ 272.4 $ 395.5 $ 118.9 Storm Costs, Net 1,379.1 799.3 484.4 95.4 1,102.7 695.6 341.3 65.8 Regulatory Tracking Mechanisms 1,075.3 216.8 391.5 73.7 1,050.5 333.6 376.6 85.4 Income Taxes, Net 853.3 491.1 115.6 16.0 790.7 470.5 112.6 17.5 Securitized Stranded Costs 435.7 — — 435.7 478.9 — — 478.9 Goodwill-related 281.0 — 241.2 — 297.8 — 255.7 — Derivative Liabilities 181.8 181.8 — — 249.2 249.2 — — Asset Retirement Obligations 127.9 35.9 68.2 4.4 115.0 33.6 59.8 4.1 Other Regulatory Assets 322.5 26.2 114.0 14.4 150.0 29.9 37.7 15.8 Total Regulatory Assets 5,578.3 1,907.8 1,714.4 696.2 5,715.8 2,084.8 1,579.2 786.4 Less: Current Portion 1,335.5 314.1 492.8 102.2 1,129.1 371.6 444.0 107.2 Total Long-Term Regulatory Assets $ 4,242.8 $ 1,593.7 $ 1,221.6 $ 594.0 $ 4,586.7 $ 1,713.2 $ 1,135.2 $ 679.2 Benefit Costs: Deferred benefit costs represent unrecognized actuarial losses and gains and unrecognized prior service costs and credits attributable to Eversource's Pension, SERP and PBOP Plans. The regulated companies record actuarial losses and gains and prior service costs and credits arising at the December 31st remeasurement date of the funded status of the benefit plans as a regulatory asset or regulatory liability in lieu of a charge to Accumulated Other Comprehensive Income/(Loss), reflecting ultimate recovery from customers through rates. The regulatory asset or regulatory liability is amortized with the recognition of actuarial losses and gains and prior service costs and credits to net periodic benefit expense/income over the estimated average future employee service period using the corridor approach. Regulatory accounting is also applied to the portions of Eversource's service company costs that support the regulated companies, as these amounts are also recoverable. As these regulatory assets or regulatory liabilities do not represent a cash outlay for the regulated companies, no carrying charge is recovered from customers. See Note 11A, "Employee Benefits - Pension Benefits and Postretirement Benefits Other Than Pension," for further information on regulatory benefit plan amounts arising and amortized during the year. Eversource, CL&P, NSTAR Electric, and PSNH recover benefit costs related to their distribution and transmission operations from customers in rates as allowed by their applicable regulatory commissions. NSTAR Electric, NSTAR Gas and EGMA recover qualified pension and PBOP expenses related to their distribution operations through a rate reconciling mechanism that fully tracks the change in net pension and PBOP expenses each year. The electric transmission companies' rates provide for an annual true-up of estimated to actual costs, which include pension and PBOP expenses. Storm Costs, Net: The storm cost deferrals relate to costs incurred for storm events at CL&P, NSTAR Electric and PSNH that each company expects to recover from customers. A storm must meet certain criteria to qualify for deferral and recovery with the criteria specific to each state jurisdiction and utility company. Once a storm qualifies for recovery, all qualifying expenses incurred during storm restoration efforts are deferred and recovered from customers. Costs for storms that do not meet the specific criteria are expensed as incurred. In addition to storm restoration costs, CL&P and PSNH are each allowed to recover pre-staging storm costs. Management believes all storm costs deferred were prudently incurred and meet the criteria for specific cost recovery in Connecticut, Massachusetts and New Hampshire, and that recovery from customers is probable through the applicable regulatory recovery processes. Each electric utility company either recovers a carrying charge on its deferred storm cost regulatory asset balance or the regulatory asset balance is included in rate base. Multiple tropical and severe storms over the past several years have caused extensive damage to Eversource’s electric distribution systems resulting in significant numbers and durations of customer outages, along with significant pre-staging costs. Storms in 2022 that qualified for future recovery resulted in deferred storm restoration costs and pre-staging costs totaling $399 million at Eversource, including $163 million at CL&P, $181 million at NSTAR Electric, and $55 million at PSNH. Management believes that all of these storm costs were prudently incurred and meet the criteria for specific cost recovery. Of Eversource’s total deferred storm costs, $1.40 billion either have yet to be filed with the applicable regulatory commission, are pending regulatory approval, or are subject to prudency review (including $807 million at CL&P, $492 million at NSTAR Electric and $98 million at PSNH) as of December 31, 2022. These storm cost totals exclude storm funding amounts that are collected in rates, which are recorded as a reduction to the deferred storm cost regulatory asset balance. NSTAR Electric and PSNH are seeking approval of their deferred storm restoration costs through the applicable regulatory recovery process. As part of CL&P’s October 1, 2021 settlement agreement, CL&P agreed to freeze its current base distribution rates (including storm costs) until no earlier than January 1, 2024. As a result, CL&P has not yet filed for approval of its storm costs in a regulatory proceeding. CL&P Tropical Storm Isaias Costs: On August 4, 2020, Tropical Storm Isaias caused catastrophic damage to our electric distribution system, which resulted in significant numbers and durations of customer outages, primarily in Connecticut. In terms of customer outages, this storm was one of the worst in CL&P’s history. PURA will investigate the prudency of costs incurred by CL&P to restore service in response to Tropical Storm Isaias. That investigation is expected to occur either in a separate proceeding not yet initiated or as part of CL&P’s next rate review proceeding. Tropical Storm Isaias resulted in deferred storm restoration costs of approximately $235 million at CL&P as of December 31, 2022. Although PURA found that CL&P’s performance in its preparation for, and response to, Tropical Storm Isaias fell below applicable performance standards in certain instances, CL&P believes it will be able to present credible evidence in a future proceeding demonstrating there is no reasonably close causal connection between the alleged sub-standard performance and the storm costs incurred. While it is possible that some amount of storm costs may be disallowed by PURA in a future proceeding, any such amount cannot be estimated at this time. Eversource and CL&P continue to believe that these storm restoration costs associated with Tropical Storm Isaias were prudently incurred and meet the criteria for cost recovery; and as a result, management does not expect the storm cost review by PURA to have a material impact on the financial position or results of operations of Eversource or CL&P. Regulatory Tracking Mechanisms: The regulated companies' approved rates are designed to recover costs incurred to provide service to customers. The regulated companies recover certain of their costs on a fully-reconciling basis through regulatory commission-approved tracking mechanisms. The differences between the costs incurred (or the rate recovery allowed) and the actual revenues are recorded as regulatory assets (for undercollections) or as regulatory liabilities (for overcollections) to be included in future customer rates each year. Carrying charges are recovered in rates on all material regulatory tracking mechanisms. The electric and natural gas distribution companies recover, on a fully reconciling basis, the costs associated with the procurement of energy and natural gas supply, electric transmission related costs from FERC-approved transmission tariffs, energy efficiency programs, low income assistance programs, certain uncollectible accounts receivable for hardship customers, restructuring and stranded costs as a result of deregulation (including securitized RRB charges), certain capital tracking mechanisms for infrastructure improvements, and additionally for the Massachusetts utilities, pension and PBOP benefits, net metering for distributed generation, and solar-related programs. CL&P, NSTAR Electric, Yankee Gas, NSTAR Gas, EGMA and the Aquarion Water Company of Connecticut each have a regulatory commission approved revenue decoupling mechanism. Distribution revenues are decoupled from customer sales volumes, where applicable, which breaks the relationship between sales volumes and revenues. Each company reconciles its annual base distribution rate recovery amount to the pre-established levels of baseline distribution delivery service revenues. Any difference between the allowed level of distribution revenue and the actual amount realized during a 12-month period is adjusted through rates in the following period. Income Taxes, Net: The tax effect of temporary book-tax differences (differences between the periods in which transactions affect income in the financial statements and the periods in which they affect the determination of taxable income, including those differences relating to uncertain tax positions) is accounted for in accordance with the rate-making treatment of the applicable regulatory commissions and accounting guidance for income taxes. Differences in income taxes between the accounting guidance and the rate-making treatment of the applicable regulatory commissions are recorded as regulatory assets. As these assets are offset by deferred income tax liabilities, no carrying charge is collected. The amortization period of these assets varies depending on the nature and/or remaining life of the underlying assets and liabilities. For further information regarding income taxes, see Note 12, "Income Taxes," to the financial statements. Securitized Stranded Costs: In 2018, a subsidiary of PSNH issued $635.7 million of securitized RRBs to finance PSNH's unrecovered remaining costs associated with the divestiture of its generation assets. Securitized regulatory assets, which are not earning an equity return, are being recovered over the amortization period of the associated RRBs. The PSNH RRBs are expected to be repaid by February 1, 2033. For further information, see Note 10, "Rate Reduction Bonds and Variable Interest Entities," to the financial statements. Goodwill-related: The goodwill regulatory asset originated from a 1999 transaction, and the DPU allowed its recovery in NSTAR Electric and NSTAR Gas rates. This regulatory asset is currently being amortized and recovered from customers in rates without a carrying charge over a 40-year period, and as of December 31, 2022, there were 17 years of amortization remaining. Derivative Liabilities: Regulatory assets are recorded as an offset to derivative liabilities and relate to the fair value of contracts used to purchase energy and energy-related products that will be recovered from customers in future rates. These assets are excluded from rate base and are being recovered as the actual settlements occur over the duration of the contracts. See Note 4, "Derivative Instruments," to the financial statements for further information on these contracts. Asset Retirement Obligations: The costs associated with the depreciation of the regulated companies' ARO assets and accretion of the ARO liabilities are recorded as regulatory assets in accordance with regulatory accounting guidance. The regulated companies' ARO assets, regulatory assets, and ARO liabilities offset and are excluded from rate base. These costs are being recovered over the life of the underlying property, plant and equipment. Other Regulatory Assets: Other Regulatory Assets primarily include environmental remediation costs, certain uncollectible accounts receivable for hardship customers, certain exogenous property taxes and merger-related costs allowed for recovery, contractual obligations associated with the spent nuclear fuel storage costs of the CYAPC, YAEC and MYAPC decommissioned nuclear power facilities, water tank painting costs, losses associated with the reacquisition or redemption of long-term debt, and various other items. Regulatory Costs in Long-Term Assets: Eversource's regulated companies had $210.8 million (including $135.9 million for CL&P, $19.8 million for NSTAR Electric and $1.0 million for PSNH) and $252.5 million (including $114.9 million for CL&P, $85.0 million for NSTAR Electric and $3.4 million for PSNH) of additional regulatory costs as of December 31, 2022 and 2021, respectively, that were included in long-term assets on the balance sheets. These amounts represent incurred costs for which recovery has not yet been specifically approved by the applicable regulatory agency. However, based on regulatory policies or past precedent on similar costs, management believes it is probable that these costs will ultimately be approved and recovered from customers in rates. As of December 31, 2022 and 2021, these regulatory costs included incremental COVID-19 related non-tracked uncollectible expense deferred of $29.8 million and $33.0 million at Eversource, $11.8 million and $18.0 million at CL&P, and $2.2 million and $6.1 million at NSTAR Electric, respectively. Equity Return on Regulatory Assets: For rate-making purposes, the regulated companies recover the carrying costs related to their regulatory assets. For certain regulatory assets, the carrying cost recovered includes an equity return component. This equity return is not recorded on the balance sheets. The equity return for PSNH was $4.1 million and $5.0 million as of December 31, 2022 and 2021, respectively. These carrying costs will be recovered from customers in future rates. Regulatory Liabilities: The components of regulatory liabilities were as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH EDIT due to Tax Cuts and Jobs Act of 2017 $ 2,619.3 $ 983.6 $ 944.3 $ 348.6 $ 2,685.2 $ 996.1 $ 984.5 $ 359.2 Cost of Removal 670.6 130.8 405.3 14.7 649.6 100.1 381.0 17.2 Regulatory Tracking Mechanisms 890.8 361.0 336.1 155.0 448.4 182.0 185.1 107.0 Deferred Portion of Non-Service Income 270.9 34.5 139.7 28.8 148.3 12.0 90.7 14.9 Benefit Costs 55.4 0.7 31.4 — 133.5 — 107.4 — AFUDC - Transmission 98.2 48.2 50.0 — 81.0 43.2 37.8 — CL&P Settlement Agreement and Storm — — — — 81.3 81.3 — — Other Regulatory Liabilities 215.9 40.6 14.5 6.5 241.4 45.1 0.8 3.3 Total Regulatory Liabilities 4,821.1 1,599.4 1,921.3 553.6 4,468.7 1,459.8 1,787.3 501.6 Less: Current Portion 890.8 336.0 373.2 162.0 602.4 266.5 228.2 120.2 Total Long-Term Regulatory Liabilities $ 3,930.3 $ 1,263.4 $ 1,548.1 $ 391.6 $ 3,866.3 $ 1,193.3 $ 1,559.1 $ 381.4 EDIT due to Tax Cuts and Jobs Act of 2017: Pursuant to the Tax Cuts and Jobs Act of 2017, Eversource had remeasured its existing deferred federal income tax balances to reflect the decrease in the U.S. federal corporate income tax rate from 35 percent to 21 percent. The remeasurement resulted in provisional regulated excess accumulated deferred income tax (excess ADIT or EDIT) liabilities that will benefit customers in future periods and were recognized as regulatory liabilities on the balance sheet. EDIT liabilities related to property, plant, and equipment are subject to IRS normalization rules and will be returned to customers using the same timing as the remaining useful lives of the underlying assets that gave rise to the ADIT liabilities. Eversource's regulated companies (except for the Connecticut water business) are in the process of refunding the EDIT liabilities to customers based on orders issued by applicable state and federal regulatory commissions. Cost of Removal: Eversource's regulated companies currently recover amounts in rates for future costs of removal of plant assets over the lives of the assets. The estimated cost to remove utility assets from service is recognized as a component of depreciation expense, and the cumulative amount collected from customers but not yet expended is recognized as a regulatory liability. Deferred Portion of Non-Service Income Components of Pension, SERP and PBOP: Regulatory liabilities were recorded for the deferred portion of the non-service related components of net periodic benefit expense/(income) for the Pension, SERP and PBOP Plans. These regulatory liabilities will be amortized over the remaining useful lives of the various classes of utility property, plant and equipment. AFUDC - Transmission: Regulatory liabilities were recorded by CL&P and NSTAR Electric for AFUDC accrued on certain reliability-related transmission projects to reflect local rate base recovery. These regulatory liabilities will be amortized over the depreciable life of the related transmission assets. CL&P Settlement Agreement and Storm Performance Penalty: On April 28, 2021, PURA issued a final decision on CL&P’s compliance with its emergency response plan that concluded CL&P failed to comply with certain storm performance standards and was imprudent in certain instances. A $28.4 million performance penalty assessed by PURA was recorded within current regulatory liabilities on CL&P’s balance sheet and was credited to customers on electric bills beginning on September 1, 2021 over a one-year period. On October 1, 2021, CL&P entered into a settlement agreement with the DEEP, Office of Consumer Counsel, Office of the Attorney General and the Connecticut Industrial Energy Consumers, resolving certain issues that arose in then-pending regulatory proceedings initiated by PURA. PURA approved the settlement agreement on October 27, 2021. CL&P recorded a current regulatory liability of $75 million on the balance sheet associated with the provisions of the settlement agreement. Customer credits of $65 million were distributed based on customer sales over a two-month billing period from December 1, 2021 to January 31, 2022. CL&P also irrevocably set aside $10 million in a customer assistance fund to provide bill payment assistance to certain existing non-hardship and hardship customers carrying arrearages. Those customers were provided with $10 million of bill forgiveness in the first quarter of 2022. The balance as of December 31, 2021 represented the reserve for customer credits not yet issued and bill payment assistance not yet provided. See Note 13G, “Commitments and Contingencies - CL&P Regulatory Matters,” for further information. Other Regulatory Liabilities: Other Regulatory Liabilities primarily include EGMA’s acquired regulatory liability as a result of the 2020 DPU-approved rate settlement agreement and the CMA asset acquisition on October 9, 2020, and various other items. FERC ROE Complaints : As of December 31, 2022, Eversource has a reserve established for the second ROE complaint period in the pending FERC ROE complaint proceedings, which was recorded as a regulatory liability and is reflected within Regulatory Tracking Mechanisms in the table above. The cumulative pre-tax reserve (excluding interest) as of December 31, 2022 totaled $39.1 million for Eversource (including $21.4 million for CL&P, $14.6 million for NSTAR Electric and $3.1 million for PSNH). See Note 13E, "Commitments and Contingencies – FERC ROE Complaints," for further information on developments in the pending ROE complaint proceedings. Recent Regulatory Developments: CL&P Rate Relief Plan: On November 28, 2022, Governor Lamont, DEEP, Office of Consumer Counsel, and CL&P jointly developed a rate relief plan for electric customers for the winter peak season of January 1, 2023 through April 30, 2023. On December 16, 2022, PURA approved the rate relief plan. As part of the rate relief plan, CL&P reduced the Non-Bypassable Federally Mandated Congestion Charge (NBFMCC) rate effective January 1, 2023 to provide customers with an average $10 monthly bill credit from January through April 2023. This rate reduction accelerates the return to customers of net revenues generated by long-term state-approved energy contracts with the Millstone and Seabrook nuclear power plants of approximately $90 million. The rate relief plan also included instituting a temporary, flat monthly discount for qualifying low-income hardship customers effective January 1, 2023. This flat-rate credit will continue until a new low-income discount rate that was approved by PURA in an October 19, 2022 decision is implemented in 2024. These aspects of the rate relief plan do not impact CL&P’s earnings but do impact its future cash flows. Also as part of the rate relief plan, CL&P committed to contribute $10 million to an energy assistance program for qualifying hardship customers, which is expected to be distributed as a bill credit to those customers by the end of the first quarter of 2023. CL&P recorded a current liability of $10 million on the balance sheet and a charge to expense on the statement of income for the year ended December 31, 2022 associated with the customer assistance program. NSTAR Electric Distribution Rate Case : On November 30, 2022, the DPU issued its decision in the NSTAR Electric distribution rate case and approved a base distribution rate increase of $64 million effective January 1, 2023. The DPU approved a renewal of the performance-based ratemaking (PBR) plan originally authorized in its previous rate case for a five-year term, with a corresponding stay out provision. The PBR plan term has the possibility of a five-year extension. The PBR mechanism allows for an annual adjustment to base distribution rates for inflation and exogenous events. The DPU also allowed for adjustments to the PBR mechanism for the recovery of future capital additions based on a historical five-year average of total capital additions, beginning with the January 1, 2024 PBR adjustment. The decision allows an authorized regulatory ROE of 9.80 percent on a capital structure including 53.2 percent equity. Among other items, the DPU approved an increase to the annual storm fund contribution collected through base distribution rates from $10 million to $31 million, and allowed for the recovery of storm threshold costs of $1.3 million per storm event subsequent to the eighth storm in a calendar year (six recovered in base rates plus two additional storms). The DPU approved cost recovery of a portion of NSTAR Electric’s outstanding storm costs beginning on January 1, 2023 and January 1, 2024, subject to reconciliation from future prudency reviews. In a subsequent compliance filing, the DPU allowed recovery to commence for outstanding storm costs occurring between 2018 and 2022 and interest in a total of $162.1 million over a five-year period starting January 1, 2023. In addition, NSTAR Electric will begin to recover 2021 exogenous storms and interest in a total of $220.9 million over a five-year period beginning January 1, 2024. The DPU also approved the recovery of historical exogenous property taxes of $30.8 million incurred from 2020 through 2022 over a two-year period and $8.3 million incurred from 2012 through 2015 over a five-year period effective January 1, 2023. As a result of this decision, these deferred property taxes were reclassified from Other Long-Term Assets to Regulatory Assets on the NSTAR Electric balance sheet. NSTAR Gas Distribution Rates: As part of an inflation-based mechanism, NSTAR Gas submitted its second annual Performance Based Rate Adjustment filing on September 15, 2022 and on October 31, 2022, the DPU approved a $21.7 million increase to base distribution rates for effect on November 1, 2022. The increase is inclusive of a $4.5 million permanent increase related to exogenous property taxes and a $5.4 million increase related to an October 6, 2021 mitigation plan filing that delayed recovery of a portion of a base distribution rate increase originally scheduled to take effect November 1, 2021. The DPU also approved the recovery of historical exogenous property taxes incurred from November 1, 2020 through October 31, 2022 of $8.2 million over a two-year period through a separate reconciling mechanism effective November 1, 2022. As a result of this decision, these deferred property taxes were reclassified from Other Long-Term Assets to Regulatory Assets on the Eversource balance sheet. EGMA Distribution Rates: As established in an October 7, 2020 EGMA Rate Settlement Agreement approved by the DPU, on September 16, 2022 EGMA filed for its second base distribution rate increase and on October 31, 2022, the DPU approved a $6.7 million increase to base distribution rates and a $3.3 million increase to the Tax Act Credit Factor for effect on November 1, 2022. The DPU also approved the recovery of historical exogenous property taxes incurred from November 1, 2020 through October 31, 2022 of $8.6 million over a two-year period through a separate reconciling mechanism effective November 1, 2022. EGMA will request recovery of incremental property taxes incurred after October 31, 2022 in future exogenous filings. As a result of this decision, these deferred property taxes were reclassified from Other Long-Term Assets to Regulatory Assets on the Eversource balance sheet.

PROPERTY, PLANT AND EQUIPMENT A

PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION	PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION Utility property, plant and equipment is recorded at original cost. Original cost includes materials, labor, construction overheads and AFUDC for regulated property. The cost of repairs and maintenance is charged to Operations and Maintenance expense as incurred. The following tables summarize property, plant and equipment by asset category: Eversource As of December 31, (Millions of Dollars) 2022 2021 Distribution - Electric $ 18,326.2 $ 17,679.1 Distribution - Natural Gas 7,443.8 6,694.8 Transmission - Electric 13,709.3 12,882.4 Distribution - Water 2,112.6 1,900.9 Solar 200.8 200.9 Utility 41,792.7 39,358.1 Other (1) 1,738.1 1,469.5 Property, Plant and Equipment, Gross 43,530.8 40,827.6 Less: Accumulated Depreciation Utility (9,167.4) (8,885.2) Other (706.1) (580.1) Total Accumulated Depreciation (9,873.5) (9,465.3) Property, Plant and Equipment, Net 33,657.3 31,362.3 Construction Work in Progress 2,455.5 2,015.4 Total Property, Plant and Equipment, Net $ 36,112.8 $ 33,377.7 As of December 31, 2022 2021 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH Distribution - Electric $ 7,370.1 $ 8,410.0 $ 2,586.4 $ 7,117.6 $ 8,105.5 $ 2,496.2 Transmission - Electric 6,165.1 5,333.8 2,212.0 5,859.0 5,090.5 1,934.6 Solar — 200.8 — — 200.9 — Property, Plant and Equipment, Gross 13,535.2 13,944.6 4,798.4 12,976.6 13,396.9 4,430.8 Less: Accumulated Depreciation (2,567.1) (3,381.2) (912.3) (2,572.1) (3,227.3) (908.4) Property, Plant and Equipment, Net 10,968.1 10,563.4 3,886.1 10,404.5 10,169.6 3,522.4 Construction Work in Progress 498.9 1,063.6 174.1 399.0 707.0 134.1 Total Property, Plant and Equipment, Net $ 11,467.0 $ 11,627.0 $ 4,060.2 $ 10,803.5 $ 10,876.6 $ 3,656.5 (1) These assets are primarily comprised of computer software, hardware and equipment at Eversource Service and buildings at The Rocky River Realty Company. Depreciation: Depreciation of utility assets is calculated on a straight-line basis using composite rates based on the estimated remaining useful lives of the various classes of property (estimated useful life for PSNH distribution and the water utilities). The composite rates, which are subject to approval by the appropriate state regulatory agency, include a cost of removal component, which is collected from customers over the lives of the plant assets and is recognized as a regulatory liability. Depreciation rates are applied to property from the time it is placed in service. Upon retirement from service, the cost of the utility asset is charged to the accumulated provision for depreciation. The actual incurred removal costs are applied against the related regulatory liability. The depreciation rates for the various classes of utility property, plant and equipment aggregate to composite rates as follows: (Percent) 2022 2021 2020 Eversource 3.0 % 3.1 % 3.0 % CL&P 2.8 % 2.8 % 2.8 % NSTAR Electric 2.7 % 2.8 % 2.8 % PSNH 3.0 % 3.1 % 2.8 % The following table summarizes average remaining useful lives of depreciable assets: As of December 31, 2022 (Years) Eversource CL&P NSTAR Electric PSNH Distribution - Electric 34.2 35.0 34.6 30.8 Distribution - Natural Gas 37.4 — — — Transmission - Electric 39.8 36.3 45.2 39.3 Distribution - Water 39.0 — — — Solar 22.9 — 22.9 — Other (1) 11.0 — — — (1) The estimated useful life of computer software, hardware and equipment primarily ranges from 5 to 15 years and of buildings is 40 years.

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	12 Months Ended
	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS	DERIVATIVE INSTRUMENTS The electric and natural gas companies purchase and procure energy and energy-related products, which are subject to price volatility, for their customers. The costs associated with supplying energy to customers are recoverable from customers in future rates. These regulated companies manage the risks associated with the price volatility of energy and energy-related products through the use of derivative and non-derivative contracts. Many of the derivative contracts meet the definition of, and are designated as, normal and qualify for accrual accounting under the applicable accounting guidance. The costs and benefits of derivative contracts that meet the definition of normal are recognized in Operating Expenses on the statements of income as electricity or natural gas is delivered. Derivative contracts that are not designated as normal are recorded at fair value as current or long-term Derivative Assets or Derivative Liabilities on the balance sheets. For the electric and natural gas companies, regulatory assets or regulatory liabilities are recorded to offset the fair values of derivatives, as contract settlement amounts are recovered from, or refunded to, customers in their respective energy supply rates. The gross fair values of derivative assets and liabilities with the same counterparty are offset and reported as net Derivative Assets or Derivative Liabilities, with current and long-term portions, on the balance sheets. The following table presents the gross fair values of contracts, categorized by risk type, and the net amounts recorded as current or long-term derivative assets or liabilities: As of December 31, 2022 2021 CL&P (Millions of Dollars) Fair Value Hierarchy Commodity Supply Netting (1) Net Amount Commodity Supply Netting (1) Net Amount Current Derivative Assets Level 3 $ 16.3 $ (0.5) $ 15.8 $ 14.7 $ (1.0) $ 13.7 Long-Term Derivative Assets Level 3 28.8 (0.9) 27.9 46.9 (0.9) 46.0 Current Derivative Liabilities Level 3 (81.6) — (81.6) (73.5) — (73.5) Long-Term Derivative Liabilities Level 3 (143.9) — (143.9) (235.4) — (235.4) (1) Amounts represent derivative assets and liabilities that Eversource elected to record net on the balance sheets. These amounts are subject to master netting agreements or similar agreements for which the right of offset exists. The business activities that result in the recognition of derivative assets also create exposure to various counterparties. As of December 31, 2022, CL&P's derivative assets were exposed to counterparty credit risk and contracted with investment grade entities. Derivative Contracts at Fair Value with Offsetting Regulatory Amounts Commodity Supply and Price Risk Management : As required by regulation, CL&P, along with UI, has capacity-related contracts with generation facilities. CL&P has a sharing agreement with UI, with 80 percent of the costs or benefits of each contract borne by or allocated to CL&P and 20 percent borne by or allocated to UI. The combined capacities of these contracts as of December 31, 2022 and 2021 were 674 MW and 675 MW, respectively. The capacity contracts extend through 2026 and obligate both CL&P and UI to make or receive payments on a monthly basis to or from the generation facilities based on the difference between a set capacity price and the capacity market price received in the ISO-NE capacity markets. For the years ended December 31, 2022, 2021 and 2020, there were gains of $10.1 million and losses of $7.1 million and $21.2 million, respectively, deferred as regulatory costs, which reflect the change in fair value associated with Eversource's derivative contracts. Fair Value Measurements of Derivative Instruments The fair value of derivative contracts classified as Level 3 utilizes both significant observable and unobservable inputs. The fair value is modeled using income techniques, such as discounted cash flow valuations adjusted for assumptions related to exit price. Valuations of derivative contracts using a discounted cash flow methodology include assumptions regarding the timing and likelihood of scheduled payments and also reflect non-performance risk, including credit, using the default probability approach based on the counterparty’s credit rating for assets and the Company’s credit rating for liabilities. Significant observable inputs for valuations of these contracts include energy-related product prices in future years for which quoted prices in an active market exist. Valuations incorporate estimates of premiums or discounts that would be required by a market participant to arrive at an exit price, using historical market transactions adjusted for the terms of the contract. Fair value measurements categorized in Level 3 of the fair value hierarchy are prepared by individuals with expertise in valuation techniques, pricing of energy-related products, and accounting requirements. The following is a summary of the significant unobservable inputs utilized in the valuations of the derivative contracts classified as Level 3: As of December 31, 2022 2021 CL&P Range Average Period Covered Range Average Period Covered Forward Reserve Prices $ 0.44 — $0.50 $ 0.47 per kW-Month 2023 - 2024 $ 0.50 — $1.15 $ 0.82 per kW-Month 2022 - 2024 Exit price premiums of 2.9 percent through 7.1 percent, or a weighted average of 6.1 percent, are also Level 3 significant unobservable inputs applied to these contracts and reflect the uncertainty and illiquidity premiums that would be required based on the most recent market activity available for similar type contracts. The risk premium was weighted by the relative fair value of the net derivative instruments. As of December 31, 2021, Level 3 unobservable inputs also utilized in the valuation of CL&P’s capacity-related contracts included capacity prices of $2.61 per kW-Month over the period 2025 through 2026. Beginning in the first quarter of 2022, these capacity price inputs are now observable. Significant increases or decreases in future capacity or forward reserve prices in isolation would decrease or increase, respectively, the fair value of the derivative liability. Any increases in risk premiums would increase the fair value of the derivative liability. Changes in these fair values are recorded as a regulatory asset or liability and do not impact net income. The following table presents changes in the Level 3 category of derivative assets and derivative liabilities measured at fair value on a recurring basis. The derivative assets and liabilities are presented on a net basis. CL&P (Millions of Dollars) For the Years Ended December 31, 2022 2021 Derivatives, Net: Fair Value as of Beginning of Period $ (249.2) $ (293.1) Net Realized/Unrealized Gains/(Losses) Included in Regulatory Assets 10.1 (8.5) Settlements 57.3 52.4 Fair Value as of End of Period $ (181.8) $ (249.2)

MARKETABLE SECURITIES

MARKETABLE SECURITIES	12 Months Ended
	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
MARKETABLE SECURITIES	MARKETABLE SECURITIES Eversource holds marketable securities that are primarily used to fund certain non-qualified executive benefits. The trusts that hold these marketable securities are not subject to regulatory oversight by state or federal agencies. Eversource’s marketable securities also include the CYAPC and YAEC legally restricted trusts that each hold equity and available-for-sale debt securities to fund the spent nuclear fuel removal obligations of their nuclear fuel storage facilities. Equity and available-for-sale debt marketable securities are recorded at fair value, with the current portion recorded in Prepayments and Other Current Assets and the long-term portion recorded in Marketable Securities on the balance sheets. Equity Securities: Unrealized gains and losses on equity securities held in Eversource's non-qualified executive benefit trust are recorded in Other Income, Net on the statements of income. The fair value of these equity securities as of December 31, 2022 and 2021 was $20.0 million and $40.2 million, respectively. For the years ended December 31, 2022, 2021 and 2020, there were unrealized losses of $9.7 million and unrealized gains of $4.4 million and $3.7 million recorded in Other Income, Net related to these equity securities, respectively. Eversource's equity securities also include CYAPC's and YAEC's marketable securities held in spent nuclear fuel trusts, which had fair values of $170.1 million and $214.0 million as of December 31, 2022 and 2021, respectively. Unrealized gains and losses for these spent nuclear fuel trusts are subject to regulatory accounting treatment and are recorded in Marketable Securities with the corresponding offset to long-term liabilities on the balance sheets, with no impact on the statements of income. Available-for-Sale Debt Securities: The following is a summary of the available-for-sale debt securities: As of December 31, 2022 2021 Eversource (Millions of Dollars) Amortized Pre-Tax Pre-Tax Fair Value Amortized Pre-Tax Pre-Tax Fair Value Debt Securities $ 201.6 $ 0.1 $ (16.2) $ 185.5 $ 214.5 $ 5.1 $ (0.2) $ 219.4 Unrealized gains and losses on available-for-sale debt securities held in Eversource's non-qualified executive benefit trust are recorded in Accumulated Other Comprehensive Income, excluding amounts related to credit losses or losses on securities intended to be sold, which are recorded in Other Income, Net. There have been no credit losses for the years ended December 31, 2022 and 2021, and no allowance for credit losses as of December 31, 2022. Factors considered in determining whether a credit loss exists include adverse conditions specifically affecting the issuer, the payment history, ratings and rating changes of the security, and the severity of the impairment. For asset-backed debt securities, underlying collateral and expected future cash flows are also evaluated. Debt securities included in Eversource's non-qualified benefit trust portfolio are investment-grade bonds with a lower default risk based on their credit quality. Eversource's debt securities also include CYAPC's and YAEC's marketable securities held in spent nuclear fuel trusts in the amounts of $163.2 million and $189.9 million as of December 31, 2022 and 2021, respectively. Unrealized gains and losses for available-for-sale debt securities included in the CYAPC and YAEC spent nuclear fuel trusts are subject to regulatory accounting treatment and are recorded in Marketable Securities with the corresponding offset to long-term liabilities on the balance sheets, with no impact on the statements of income. Pre-tax unrealized gains and losses as of December 31, 2022 and 2021 primarily relate to the debt securities included in CYAPC's and YAEC's spent nuclear fuel trusts. As of December 31, 2022, the contractual maturities of available-for-sale debt securities were as follows: Eversource (Millions of Dollars) Amortized Fair Less than one year (1) $ 28.5 $ 28.3 One to five years 43.8 42.4 Six to ten years 35.6 32.3 Greater than ten years 93.7 82.5 Total Debt Securities $ 201.6 $ 185.5 (1) Amounts in the Less than one year category include securities in the CYAPC and YAEC spent nuclear fuel trusts, which are restricted and are classified in long-term Marketable Securities on the balance sheets. Realized Gains and Losses: Realized gains and losses are recorded in Other Income, Net for Eversource's benefit trust and are offset in long-term liabilities for CYAPC and YAEC. Eversource utilizes the specific identification basis method for the Eversource non-qualified benefit trust, and the average cost basis method for the CYAPC and YAEC spent nuclear fuel trusts to compute the realized gains and losses on the sale of marketable securities. Fair Value Measurements: The following table presents the marketable securities recorded at fair value on a recurring basis by the level in which they are classified within the fair value hierarchy: Eversource (Millions of Dollars) As of December 31, 2022 2021 Level 1: Mutual Funds and Equities $ 190.1 $ 254.2 Money Market Funds 25.4 31.3 Total Level 1 $ 215.5 $ 285.5 Level 2: U.S. Government Issued Debt Securities (Agency and Treasury) $ 82.3 $ 81.3 Corporate Debt Securities 46.1 65.3 Asset-Backed Debt Securities 8.6 12.6 Municipal Bonds 12.7 12.3 Other Fixed Income Securities 10.4 16.6 Total Level 2 $ 160.1 $ 188.1 Total Marketable Securities $ 375.6 $ 473.6

INVESTMENTS IN UNCONSOLIDATED A

INVESTMENTS IN UNCONSOLIDATED AFFILIATES	12 Months Ended
	Dec. 31, 2022
Equity Method Investments and Joint Ventures [Abstract]
INVESTMENTS IN UNCONSOLIDATED AFFILIATES	INVESTMENTS IN UNCONSOLIDATED AFFILIATES Investments in entities that are not consolidated are included in long-term assets on the balance sheets and earnings impacts from these equity investments are included in Other Income, Net on the statements of income. Eversource's investments included the following: Investment Balance as of December 31, (Millions of Dollars) Ownership Interest 2022 2021 Offshore Wind Business - North East Offshore 50 % $ 1,947.1 $ 1,213.6 Natural Gas Pipeline - Algonquin Gas Transmission, LLC 15 % 118.8 121.9 Renewable Energy Investment Fund 90 % 84.1 76.5 Other various 26.1 24.3 Total Investments in Unconsolidated Affiliates $ 2,176.1 $ 1,436.3 For the years ended December 31, 2022, 2021 and 2020, Eversource had equity in earnings of unconsolidated affiliates of $22.9 million, $14.2 million, and $14.2 million, respectively. Eversource received dividends from its equity method investees of $26.2 million, $21.6 million, and $21.8 million, respectively, for the years ended December 31, 2022, 2021 and 2020. Investments in affiliates where Eversource has the ability to exercise significant influence, but not control, over an investee are initially recognized as an equity method investment at cost. Any differences between the cost of an investment and the amount of underlying equity in net assets of an investee are considered basis differences, and are determined based upon the estimated fair values of the investee's identifiable assets and liabilities. The carrying amount of Eversource’s offshore wind investments exceeded its share of underlying equity in net assets by $343.1 million and $300.4 million, respectively, as of December 31, 2022 and 2021. As of December 31, 2022, these basis differences are primarily comprised of $168.9 million of equity method goodwill that is not being amortized, intangible assets for PPAs, and capitalized interest. Offshore Wind Business: Eversource's offshore wind business includes a 50 percent ownership interest in North East Offshore, which holds PPAs and contracts for the Revolution Wind, South Fork Wind and Sunrise Wind projects, as well as an undeveloped offshore lease area. The offshore wind investment includes capital expenditures for the three offshore wind projects, as well as capitalized costs related to future development, acquisition costs of offshore lease areas, and capitalized interest. Cash flows used in investing activities presented in Investments in Unconsolidated Affiliates on the statements of cash flows primarily relates to capital contributions in the offshore wind investment. On May 4, 2022, Eversource announced that it had initiated a strategic review of its offshore wind investment portfolio. As part of that review, Eversource is exploring strategic alternatives that could result in a potential sale of all, or part, of its 50 percent interest in its offshore wind partnership with Ørsted. In late July, Eversource started preliminary and targeted outreach to interested parties. Eversource continues to work with interested parties through this ongoing process and expects to complete this review in the second quarter of 2023. Eversource’s strategic review of its offshore wind investment does not impact the presentation of the December 31, 2022 financial statements. NSTAR Electric: As of December 31, 2022 and 2021, NSTAR Electric's investments included a 14.5 percent ownership interest in two companies that transmit hydro-electricity imported from the Hydro-Quebec system in Canada of $9.3 million and $9.0 million, respectively. Impairment of Equity Method Investments: Equity method investments are assessed for impairment when conditions exist that indicate that the fair value of the investment is less than book value. If the decline in value is considered to be other-than-temporary, the investment is written down to its estimated fair value, which establishes a new cost basis in the investment. Impairment evaluations involve a significant degree of judgment and estimation, including identifying circumstances that indicate an impairment may exist at the equity method investment level, selecting discount rates used to determine fair values, and developing an estimate of discounted future cash flows expected from investment operations or the sale of the investment. No impairments occurred during the year 2022. Eversource continually monitors and evaluates its equity method investments to determine if there are indicators of an other-than-temporary impairment. Eversource believes that the fair market value of its offshore wind investment is greater than the carrying value based upon management’s expectation for future cash flows arising from the sale of all, or part, of its investment. There are uncertainties in a sale process, and there could be changes in market conditions that would impact Eversource’s ability to sell this investment or the value it would receive for these assets. In the event that the strategic review does not result in the sale of the offshore wind business or that a sale of the offshore wind business is significantly delayed or at lower than expected value from these changes in market conditions driven by unfavorable developments, such as scheduling or permitting delays, increases in cost estimates, changes to tax laws impacting the project’s ability to monetize tax attributes, higher interest rates, and increases in the discount rate, it could result in Eversource having to evaluate whether or not its investment is impaired. Any resulting impairment charge could have a material adverse effect on the financial position and results of operations.

ASSET RETIREMENT OBLIGATIONS

ASSET RETIREMENT OBLIGATIONS	12 Months Ended
	Dec. 31, 2022
Asset Retirement Obligation Disclosure [Abstract]
ASSET RETIREMENT OBLIGATIONS	ASSET RETIREMENT OBLIGATIONS Eversource, including CL&P, NSTAR Electric and PSNH, recognizes a liability for the fair value of an ARO on the obligation date if the liability's fair value can be reasonably estimated, even if it is conditional on a future event. Settlement dates and future costs are reasonably estimated when sufficient information becomes available. Management has identified various categories of AROs, primarily CYAPC's and YAEC's obligation to dispose of spent nuclear fuel and high level waste, and also certain assets containing asbestos and hazardous contamination. Management has performed fair value calculations reflecting expected probabilities for settlement scenarios. The fair value of an ARO is recorded as a long-term liability with a corresponding amount included in Property, Plant and Equipment, Net on the balance sheets. The ARO assets are depreciated, and the ARO liabilities are accreted over the estimated life of the obligation and the corresponding credits are recorded as accumulated depreciation and ARO liabilities, respectively. As the electric and natural gas companies are rate-regulated on a cost-of-service basis, these companies apply regulatory accounting guidance and both the depreciation and accretion costs associated with these companies' AROs are recorded as increases to Regulatory Assets on the balance sheets. A reconciliation of the beginning and ending carrying amounts of ARO liabilities is as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Balance as of Beginning of Year $ 500.1 $ 35.0 $ 97.5 $ 4.7 $ 499.7 $ 33.4 $ 91.8 $ 4.4 Liabilities Settled During the Year (22.3) — — — (23.9) (0.6) — — Accretion 28.9 2.4 4.1 0.2 29.4 2.2 4.0 0.3 Revisions in Estimated Cash Flows (4.0) — (0.3) — (5.1) — 1.7 — Balance as of End of Year $ 502.7 $ 37.4 $ 101.3 $ 4.9 $ 500.1 $ 35.0 $ 97.5 $ 4.7 Eversource's amounts include CYAPC and YAEC's AROs of $320.5 million and $325.9 million as of December 31, 2022 and 2021, respectively. The fair value of the ARO for CYAPC and YAEC includes uncertainties of the fuel off-load dates related to the DOE's timing of performance regarding its obligation to dispose of the spent nuclear fuel and high level waste and other assumptions, including discount rates. The incremental asset recorded as an offset to the ARO liability was fully depreciated since the plants have no remaining useful life. Any changes in the ARO liability are recorded with a corresponding offset to the related regulatory asset. The assets held in the CYAPC and YAEC spent nuclear fuel trusts are restricted for settling the ARO and all other nuclear fuel storage obligations. For further information on the assets held in the spent nuclear fuel trusts, see Note 5, "Marketable Securities," to the financial statements.

SHORT-TERM DEBT

SHORT-TERM DEBT	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
SHORT-TERM DEBT	SHORT-TERM DEBT Short-Term Debt - Borrowing Limits: The amount of short-term borrowings that may be incurred by CL&P and NSTAR Electric is subject to periodic approval by the FERC. Because the NHPUC has jurisdiction over PSNH's short-term debt, PSNH is not currently required to obtain FERC approval for its short-term borrowings. On December 3, 2021, the FERC granted authorization that allows CL&P to issue total short-term borrowings in an aggregate principal amount not to exceed $600 million outstanding at any one time, through December 31, 2023. On December 3, 2021, the FERC granted authorization that allows NSTAR Electric to issue total short-term borrowings in an aggregate principal amount not to exceed $655 million outstanding at any one time, through December 31, 2023. PSNH is authorized by regulation of the NHPUC to incur short-term borrowings up to 10 percent of net fixed plant plus an additional $60 million until further ordered by the NHPUC. As of December 31, 2022, PSNH's short-term debt authorization under the 10 percent of net fixed plant test plus $60 million totaled $443.5 million. CL&P's certificate of incorporation contains preferred stock provisions restricting the amount of unsecured debt that CL&P may incur, including limiting unsecured indebtedness with a maturity of less than 10 years to 10 percent of total capitalization. As of December 31, 2022, CL&P had $1.01 billion of unsecured debt capacity available under this authorization. Yankee Gas, NSTAR Gas and EGMA are not required to obtain approval from any state or federal authority to incur short-term debt. Short-Term Debt - Commercial Paper Programs and Credit Agreements : Eversource parent has a $2.00 billion commercial paper program allowing Eversource parent to issue commercial paper as a form of short-term debt. Eversource parent, CL&P, PSNH, NSTAR Gas, Yankee Gas, EGMA and Aquarion Water Company of Connecticut are parties to a five-year $2.00 billion revolving credit facility, which terminates on October 15, 2027. This re volving credit facility serves to backstop Eversource parent's $2.00 billion commercial paper program. NSTAR Electric has a $650 million commercial paper program allowing NSTAR Electric to issue commercial paper as a form of short-term debt. NSTAR Electric is also a party to a five-year $650 million revolving credit facility, which terminates on October 15, 2027. This revolving credit facility serves to backstop NSTAR Electric's $650 million commercial paper program. The amount of borrowings outstanding and available under the commercial paper programs were as follows: Borrowings Outstanding Available Borrowing Capacity as of December 31, Weighted-Average Interest Rate as of December 31, (Millions of Dollars) 2022 2021 2022 2021 2022 2021 Eversource Parent Commercial Paper Program $ 1,442.2 $ 1,343.0 $ 557.8 $ 657.0 4.63 % 0.31 % NSTAR Electric Commercial Paper Program — 162.5 650.0 487.5 — % 0.14 % There were no borrowings outstanding on the revolving credit facilities as of December 31, 2022 or 2021. CL&P and PSNH have uncommitted line of credit agreements totaling $450 million and $300 million, respectively, which will expire on May 12, 2023. There are no borrowings outstanding on either the CL&P or PSNH uncommitted line of credit agreements as of December 31, 2022. Amounts outstanding under the commercial paper programs are included in Notes Payable and classified in current liabilities on the Eversource and NSTAR Electric balance sheets, as all borrowings are outstanding for no more than 364 days at one time. Under the credit facilities described above, Eversource and its subsidiaries, including CL&P, NSTAR Electric, PSNH, NSTAR Gas, EGMA, Yankee Gas, and Aquarion Water Company of Connecticut, must comply with certain financial and non-financial covenants, including a consolidated debt to total capitalization ratio. As of December 31, 2022 and 2021, Eversource and its subsidiaries were in compliance with these covenants. If Eversource or its subsidiaries were not in compliance with these covenants, an event of default would occur requiring all outstanding borrowings by such borrower to be repaid, and additional borrowings by such borrower would not be permitted under its respective credit facility. Intercompany Borrowings: Eversource parent uses its available capital resources to provide loans to its subsidiaries to assist in meeting their short-term borrowing needs. Eversource parent records intercompany interest income from its loans to subsidiaries, which is eliminated in consolidation. Intercompany loans from Eversource parent to its subsidiaries are eliminated in consolidation on Eversource's balance sheets. As of December 31, 2022, there were intercompany loans from Eversource parent to PSNH of $173.3 million. As of December 31, 2021, there were intercompany loans from Eversource parent to PSNH of $110.6 million. Intercompany loans from Eversource parent are included in Notes Payable to Eversource Parent and classified in current liabilities on the respective subsidiary's balance sheets.

LONG-TERM DEBT

LONG-TERM DEBT	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
LONG-TERM DEBT	LONG-TERM DEBT Details of long-term debt outstanding are as follows: CL&P (Millions of Dollars) As of December 31, Interest Rate 2022 2021 First Mortgage Bonds: 1994 Series D due 2024 7.875 % $ 139.8 $ 139.8 2004 Series B due 2034 5.750 % 130.0 130.0 2005 Series B due 2035 5.625 % 100.0 100.0 2006 Series A due 2036 6.350 % 250.0 250.0 2007 Series B due 2037 5.750 % 150.0 150.0 2007 Series D due 2037 6.375 % 100.0 100.0 2013 Series A due 2023 2.500 % 400.0 400.0 2014 Series A due 2044 4.300 % 475.0 475.0 2015 Series A due 2045 4.150 % 350.0 350.0 2017 Series A due 2027 3.200 % 500.0 500.0 2018 Series A due 2048 4.000 % 800.0 800.0 2020 Series A due 2025 0.750 % 400.0 400.0 2021 Series A due 2031 2.050 % 425.0 425.0 Total First Mortgage Bonds 4,219.8 4,219.8 Less Amounts due Within One Year (400.0) — Current Portion Classified as Long-Term Debt (1) 400.0 — Unamortized Premiums and Discounts, Net 21.5 23.1 Unamortized Debt Issuance Costs (24.8) (27.5) CL&P Long-Term Debt $ 4,216.5 $ 4,215.4 NSTAR Electric (Millions of Dollars) As of December 31, Interest Rate 2022 2021 Debentures: 2006 Debentures due 2036 5.750 % $ 200.0 $ 200.0 2010 Debentures due 2040 5.500 % 300.0 300.0 2012 Debentures due 2022 2.375 % — 400.0 2014 Debentures due 2044 4.400 % 300.0 300.0 2015 Debentures due 2025 3.250 % 250.0 250.0 2016 Debentures due 2026 2.700 % 250.0 250.0 2017 Debentures due 2027 3.200 % 700.0 700.0 2019 Debentures due 2029 3.250 % 400.0 400.0 2020 Debentures due 2030 3.950 % 400.0 400.0 2021 Debentures due 2051 3.100 % 300.0 300.0 2021 Debentures due 2031 1.950 % 300.0 300.0 2022 Debentures due 2052 4.550 % 450.0 — 2022 Debentures due 2052 4.950 % 400.0 — Total Debentures 4,250.0 3,800.0 Notes: 2004 Senior Notes Series B due 2034 5.900 % 50.0 50.0 2007 Senior Notes Series D due 2037 6.700 % 40.0 40.0 2013 Senior Notes Series G due 2023 3.880 % 80.0 80.0 2016 Senior Notes Series H due 2026 2.750 % 50.0 50.0 Total Notes 220.0 220.0 Less Amounts due Within One Year (80.0) (400.0) Unamortized Premiums and Discounts, Net (14.8) (11.2) Unamortized Debt Issuance Costs (30.1) (23.4) NSTAR Electric Long-Term Debt $ 4,345.1 $ 3,585.4 PSNH (Millions of Dollars) As of December 31, Interest Rate 2022 2021 First Mortgage Bonds: 2005 Series M due 2035 5.600 % $ 50.0 $ 50.0 2013 Series S due 2023 3.500 % 325.0 325.0 2019 Series T due 2049 3.600 % 300.0 300.0 2020 Series U due 2050 2.400 % 150.0 150.0 2021 Series V due 2031 2.200 % 350.0 350.0 Total First Mortgage Bonds 1,175.0 1,175.0 Less Amounts due Within One Year (325.0) — Current Portion Classified as Long-Term Debt (1) 295.3 — Unamortized Premiums and Discounts, Net (2.5) (2.6) Unamortized Debt Issuance Costs (7.9) (8.6) PSNH Long-Term Debt $ 1,134.9 $ 1,163.8 OTHER (Millions of Dollars) As of December 31, Interest Rate 2022 2021 Yankee Gas - First Mortgage Bonds due 2024 - 2051 1.380 % - 5.350% $ 845.0 $ 765.0 NSTAR Gas - First Mortgage Bonds due 2025 - 2051 2.250 % - 7.110% 705.0 580.0 EGMA - First Mortgage Bonds due 2031 - 2052 2.110 % - 4.700% 650.0 550.0 Aquarion - Senior Notes due 2024 4.000% 360.0 360.0 Aquarion - Unsecured Notes due 2023 - 2052 — % - 6.430% 464.7 394.9 Aquarion - Secured Debt due 2023 - 2044 2.864 % - 9.290% 34.4 39.6 Eversource Parent - Senior Notes due 2023 - 2050 0.800 % - 4.600% 8,150.0 6,100.0 Pre-1983 Spent Nuclear Fuel Obligation (CYAPC) 11.9 11.7 Fair Value Adjustment (2) 26.2 43.8 Less Fair Value Adjustment - Current Portion (2) (7.0) (17.7) Less Amounts due in One Year (1,203.4) (775.4) Unamortized Premiums and Discounts, Net 40.1 43.4 Unamortized Debt Issuance Costs (49.4) (36.3) Total Other Long-Term Debt $ 10,027.5 $ 8,059.0 Total Eversource Long-Term Debt $ 19,724.0 $ 17,023.6 (1) As a result of the CL&P and PSNH long-term debt issuances in January 2023, $400 million and $295.3 million, respectively, of current portion of long-term debt were reclassified as Long-Term Debt on CL&P’s and PSNH’s balance sheets as of December 31, 2022. (2) The fair value adjustment amount is the purchase price adjustments, net of amortization, required to record long-term debt at fair value on the dates of the 2012 merger with NSTAR and the 2017 acquisition of Aquarion. Availability under Long-Term Debt Issuance Authorizations: On December 14, 2022, the NHPUC approved PSNH’s request for authorization to issue up to $600 million in long-term debt through December 31, 2023. On November 30, 2022, the PURA approved CL&P's request for authorization to issue up to $1.15 billion in long-term debt through December 31, 2024. On June 14, 2022, the DPU approved NSTAR Gas’ request for authorization to issue up to $325 million in long-term debt through December 31, 2024. The remaining Eversource operating companies, including NSTAR Electric, have utilized the long-term debt authorizations in place with the respective regulatory commissions. Long-Term Debt Issuances and Repayments: The following table summarizes long-term debt issuances and repayments: (Millions of Dollars) Interest Rate Issuance/ Issue Date or Repayment Date Maturity Date Use of Proceeds for Issuance/ CL&P 2023 Series A First Mortgage Bonds 5.25 % $ 500.0 January 2023 January 2053 Repaid 2013 Series A Bonds at maturity and short-term debt, and paid capital expenditures and working capital CL&P 2013 Series A First Mortgage Bonds 2.50 % (400.0) January 2023 January 2023 Paid at maturity NSTAR Electric 2022 Debentures 4.55 % 450.0 May 2022 June 2052 Repaid short-term debt, paid capital expenditures and working capital NSTAR Electric 2022 Debentures 4.95 % 400.0 September 2022 September 2052 Refinanced investments in eligible green expenditures, which were previously financed using short-term debt from October 1, 2020 through June 30, 2022 NSTAR Electric 2012 Debentures 2.375 % (400.0) October 2022 October 2022 Paid at maturity PSNH Series W First Mortgage Bonds 5.15 % 300.0 January 2023 January 2053 Repaid short-term debt, paid capital expenditures and working capital Eversource Parent Series V Senior Notes 2.90 % 650.0 February 2022 March 2027 Repaid Series K Senior Notes at maturity and short-term debt Eversource Parent Series W Senior Notes 3.375 % 650.0 February 2022 March 2032 Repaid Series K Senior Notes at maturity and short-term debt Eversource Parent Series X Senior Notes 4.20 % 900.0 June 2022 June 2024 Repaid short-term debt and paid working capital Eversource Parent Series Y Senior Notes 4.60 % 600.0 June 2022 July 2027 Repaid short-term debt and paid working capital Eversource Parent Series K Senior Notes 2.75 % (750.0) March 2022 March 2022 Paid at maturity Yankee Gas Series B First Mortgage Bonds 8.48 % (20.0) March 2022 March 2022 Paid at maturity Yankee Gas Series U First Mortgage Bonds 4.31 % 100.0 September 2022 September 2032 Repaid short-term debt, paid capital expenditures and for general corporate purposes EGMA Series C First Mortgage Bonds 4.70 % 100.0 June 2022 June 2052 Repaid short-term debt, paid capital expenditures and for general corporate purposes NSTAR Gas Series V First Mortgage Bonds 4.40 % 125.0 July 2022 August 2032 Repaid short-term debt, paid capital expenditures and for general corporate purposes Aquarion Water Company of New Hampshire General Mortgage Bonds 4.45 % (5.0) July 2022 July 2022 Paid at maturity Aquarion Water Company of Connecticut Senior Notes 4.69 % 70.0 August 2022 September 2052 Repaid short-term debt Long-Term Debt Provisions: The utility plant of CL&P, PSNH, Yankee Gas, NSTAR Gas, EGMA and a portion of Aquarion is subject to the lien of each company's respective first mortgage bond indenture. The Eversource parent, NSTAR Electric and a portion of Aquarion debt is unsecured. Additionally, the long-term debt agreements provide that Eversource and certain of its subsidiaries must comply with certain covenants as are customarily included in such agreements, including equity requirements for NSTAR Electric, NSTAR Gas and Aquarion. Under the equity requirements, NSTAR Electric's and Aquarion's senior notes must maintain a certain consolidated indebtedness to capitalization ratio as of the end of any fiscal quarter and NSTAR Gas' outstanding long-term debt must not exceed equity. Certain secured and unsecured long-term debt securities are callable at redemption price or are subject to make-whole provisions. No long-term debt defaults have occurred as of December 31, 2022. CYAPC's Pre-1983 Spent Nuclear Fuel Obligation: Under the Nuclear Waste Policy Act of 1982, the DOE is responsible for the selection and development of repositories for, and the disposal of, spent nuclear fuel and high-level radioactive waste. CYAPC is obligated to pay the DOE for the costs to dispose of spent nuclear fuel and high-level radioactive waste generated prior to April 7, 1983 (pre-1983 Spent Nuclear Fuel). CYAPC has partially paid this obligation and recorded an accrual for its remaining liability to the DOE. This liability accrues interest costs at the 3-month Treasury bill yield rate. For nuclear fuel used to generate electricity prior to April 7, 1983, payment may be made any time prior to the first delivery of spent fuel to the DOE. As of December 31, 2022 and 2021, as a result of consolidating CYAPC, Eversource has consolidated $11.9 million and $11.7 million, respectively, in pre-1983 spent nuclear fuel obligations to the DOE. The obligation includes accumulated interest costs of $8.8 million and $8.7 million as of December 31, 2022 and 2021, respectively. CYAPC maintains a trust to fund amounts due to the DOE for the disposal of pre-1983 spent nuclear fuel. For further information, see Note 5, "Marketable Securities," to the financial statements. Fees for disposal of nuclear fuel burned on or after April 7, 1983 were billed to member companies and paid to the DOE. Long-Term Debt Maturities: Long-term debt maturities on debt outstanding for the years 2023 through 2027 and thereafter are shown below. These amounts exclude PSNH rate reduction bonds, CYAPC pre-1983 spent nuclear fuel obligation, net unamortized premiums, discounts and debt issuance costs, and other fair value adjustments as of December 31, 2022: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2023 $ 2,008.4 $ 400.0 $ 80.0 $ 325.0 2024 1,950.0 139.8 — — 2025 1,400.2 400.0 250.0 — 2026 940.2 — 300.0 — 2027 2,539.2 500.0 700.0 — Thereafter 12,236.0 2,780.0 3,140.0 850.0 Total $ 21,074.0 $ 4,219.8 $ 4,470.0 $ 1,175.0

RATE REDUCTION BONDS AND VARIAB

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES	12 Months Ended
	Dec. 31, 2022
Rate Reduction Bonds and Variable Interest Entity [Abstract]
RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES	RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES Rate Reduction Bonds: In May 2018, PSNH Funding, a wholly-owned subsidiary of PSNH, issued $635.7 million of securitized RRBs in multiple tranches with a weighted average interest rate of 3.66 percent, and final maturity dates ranging from 2026 to 2035. The RRBs are expected to be repaid by February 1, 2033. RRB payments consist of principal and interest and are paid semi-annually, beginning on February 1, 2019. The RRBs were issued pursuant to a finance order issued by the NHPUC in January 2018 to recover remaining costs resulting from the divestiture of PSNH’s generation assets. The proceeds were used by PSNH Funding to purchase PSNH’s stranded cost asset-recovery property, including its vested property right to bill, collect and adjust a non-bypassable stranded cost recovery charge from PSNH’s retail customers. The collections are used to pay principal, interest and other costs in connection with the RRBs. The RRBs are secured by the stranded cost asset-recovery property. Cash collections from the stranded cost recovery charges and funds on deposit in trust accounts are the sole source of funds to satisfy the debt obligation. PSNH is not the owner of the RRBs, and PSNH Funding’s assets and revenues are not available to pay PSNH’s creditors. The RRBs are non-recourse senior secured obligations of PSNH Funding and are not insured or guaranteed by PSNH or Eversource Energy. PSNH Funding was formed solely to issue RRBs to finance PSNH's unrecovered remaining costs associated with the divestiture of its generation assets. PSNH Funding is considered a VIE primarily because the equity capitalization is insufficient to support its operations. PSNH has the power to direct the significant activities of the VIE and is most closely associated with the VIE as compared to other interest holders. Therefore, PSNH is considered the primary beneficiary and consolidates PSNH Funding in its consolidated financial statements. The following tables summarize the impact of PSNH Funding on PSNH's balance sheets and income statements: (Millions of Dollars) As of December 31, PSNH Balance Sheets: 2022 2021 Restricted Cash - Current Portion (included in Current Assets) $ 32.4 $ 31.1 Restricted Cash - Long-Term Portion (included in Other Long-Term Assets) 3.2 3.2 Securitized Stranded Cost (included in Regulatory Assets) 435.7 478.9 Other Regulatory Liabilities (included in Regulatory Liabilities) 6.0 5.4 Accrued Interest (included in Other Current Liabilities) 6.9 7.5 Rate Reduction Bonds - Current Portion 43.2 43.2 Rate Reduction Bonds - Long-Term Portion 410.5 453.7 (Millions of Dollars) PSNH Income Statements: For the Years Ended December 31, 2022 2021 2020 Amortization of RRB Principal (included in Amortization of Regulatory Assets, Net) $ 43.2 $ 43.2 $ 43.2 Interest Expense on RRB Principal (included in Interest Expense) 17.0 18.4 19.7 Estimated principal payments on RRBs as of December 31, 2022, is summarized annually through 2027 and thereafter as follows: (Millions of Dollars) 2023 2024 2025 2026 2027 Thereafter Total PSNH $ 43.2 $ 43.2 $ 43.2 $ 43.2 $ 43.2 $ 237.7 $ 453.7 Variable Interest Entities - Other: The Company's variable interests outside of the consolidated group include contracts that are required by regulation and provide for regulatory recovery of contract costs and benefits through customer rates. Eversource, CL&P and NSTAR Electric hold variable interests in VIEs through agreements with certain entities that own single renewable energy or peaking generation power plants, with other independent power producers and with transmission businesses. Eversource, CL&P and NSTAR Electric do not control the activities that are economically significant to these VIEs or provide financial or other support to these VIEs. Therefore, Eversource, CL&P and NSTAR Electric do not consolidate these VIEs.

EMPLOYEE BENEFITS

EMPLOYEE BENEFITS	12 Months Ended
	Dec. 31, 2022
Postemployment Benefits [Abstract]
EMPLOYEE BENEFITS	EMPLOYEE BENEFITS A. Pension Benefits and Postretirement Benefits Other Than Pension Eversource provides defined benefit retirement plans (Pension Plans) that cover eligible employees and are subject to the provisions of ERISA, as amended by the Pension Protection Act of 2006. Eversource's policy is to annually fund the Pension Plans in an amount at least equal to an amount that will satisfy all federal funding requirements. In addition to the Pension Plans, Eversource maintains non-qualified defined benefit retirement plans (SERP Plans), which provide benefits in excess of Internal Revenue Code limitations to eligible participants consisting of current and retired employees. Eversource also provides defined benefit postretirement plans (PBOP Plans) that provide life insurance and a health reimbursement arrangement created for the purpose of reimbursing retirees and dependents for health insurance premiums and certain medical expenses to eligible employees that meet certain age and service eligibility requirements. The benefits provided under the PBOP Plans are not vested, and the Company has the right to modify any benefit provision subject to applicable laws at that time. Eversource annually funds postretirement costs through tax deductible contributions to external trusts. Funded Status: The Pension, SERP and PBOP Plans are accounted for under the multiple-employer approach, with each operating company's balance sheet reflecting its share of the funded status of the plans. Although Eversource maintains marketable securities in a benefit trust, the SERP Plans do not contain any assets. For further information, see Note 5, "Marketable Securities," to the financial statements. The following tables provide information on the plan benefit obligations, fair values of plan assets, and funded status: Pension and SERP As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Change in Benefit Obligation: Benefit Obligation as of Beginning of Year $ (6,729.7) $ (1,330.9) $ (1,448.4) $ (721.0) $ (7,045.3) $ (1,477.3) $ (1,517.9) $ (748.7) Service Cost (70.1) (18.7) (13.8) (6.9) (85.8) (23.0) (15.8) (8.9) Interest Cost (154.5) (31.3) (32.8) (16.9) (130.0) (27.3) (26.8) (14.5) Actuarial Gain 1,385.8 284.1 295.5 156.7 177.1 127.8 20.8 14.7 Benefits Paid - Pension 302.5 63.3 68.4 33.9 309.5 64.6 68.7 34.7 Benefits Paid - Lump Sum 33.0 — 14.8 1.0 34.7 — 15.6 — Benefits Paid - SERP 12.9 0.3 0.2 0.4 10.1 0.3 0.2 0.4 Employee Transfers — 3.2 5.7 (3.4) — 4.0 6.8 1.3 Benefit Obligation as of End of Year $ (5,220.1) $ (1,030.0) $ (1,110.4) $ (556.2) $ (6,729.7) $ (1,330.9) $ (1,448.4) $ (721.0) Change in Pension Plan Assets: Fair Value of Pension Plan Assets as of $ 6,495.5 $ 1,323.8 $ 1,596.0 $ 694.6 $ 5,409.2 $ 1,043.1 $ 1,345.1 $ 593.7 Employer Contributions 80.0 — 15.0 — 180.0 98.9 30.0 — Actual Return on Pension Plan Assets (433.6) (85.3) (103.3) (45.1) 1,250.5 250.4 312.0 136.9 Benefits Paid - Pension (302.5) (63.3) (68.4) (33.9) (309.5) (64.6) (68.7) (34.7) Benefits Paid - Lump Sum (33.0) — (14.8) (1.0) (34.7) — (15.6) — Employee Transfers — (3.2) (5.7) 3.4 — (4.0) (6.8) (1.3) Fair Value of Pension Plan Assets as of End of Year $ 5,806.4 $ 1,172.0 $ 1,418.8 $ 618.0 $ 6,495.5 $ 1,323.8 $ 1,596.0 $ 694.6 Funded Status as of December 31st $ 586.3 $ 142.0 $ 308.4 $ 61.8 $ (234.2) $ (7.1) $ 147.6 $ (26.4) Actuarial Gains and Losses: For the year ended December 31, 2022, actuarial gains were primarily attributable to an increase in the discount rate, which resulted in a decrease to Eversource's Pension and SERP Plans’ projected benefit obligation of $1.48 billion. For the year ended December 31, 2021, actuarial gains were primarily attributable to an increase in the discount rate, which resulted in a decrease to Eversource's Pension and SERP Plans’ projected benefit obligation of $286.8 million, which was partially offset by actuarial losses resulting from changes in the mortality assumption. As of December 31, 2022 and 2021, the accumulated benefit obligation for the Pension and SERP Plans is as follows: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2022 $ 4,911.6 $ 960.7 $ 1,055.1 $ 516.9 2021 6,337.3 1,241.1 1,376.1 670.3 PBOP As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Change in Benefit Obligation: Benefit Obligation as of Beginning of Year $ (884.3) $ (165.5) $ (238.4) $ (92.3) $ (993.9) $ (178.6) $ (260.5) $ (109.5) Service Cost (11.6) (2.0) (2.0) (1.1) (13.5) (2.3) (2.4) (1.2) Interest Cost (20.2) (3.7) (5.3) (2.2) (17.4) (3.2) (4.4) (1.8) Actuarial Gain 173.6 33.0 39.4 15.2 81.4 5.8 11.5 14.6 Benefits Paid 52.1 10.4 16.6 6.0 51.7 10.9 16.3 5.6 Employee Transfers — (0.1) 0.2 (0.2) — 1.9 1.1 — Impact of Acquisitions (3.3) — — — 7.4 — — — Benefit Obligation as of End of Year $ (693.7) $ (127.9) $ (189.5) $ (74.6) $ (884.3) $ (165.5) $ (238.4) $ (92.3) Change in Plan Assets: Fair Value of Plan Assets as of Beginning of Year $ 1,138.3 $ 145.7 $ 530.0 $ 88.0 $ 1,004.1 $ 134.1 $ 464.6 $ 79.4 Actual Return on Plan Assets (119.6) (15.0) (57.0) (9.8) 183.2 24.1 84.2 14.2 Employer Contributions 3.1 — — — 2.3 — — — Benefits Paid (51.7) (10.4) (16.6) (6.0) (51.3) (10.9) (16.3) (5.6) Employee Transfers — 0.3 (0.3) 0.1 — (1.6) (2.5) — Fair Value of Plan Assets as of End of Year $ 970.1 $ 120.6 $ 456.1 $ 72.3 $ 1,138.3 $ 145.7 $ 530.0 $ 88.0 Funded Status as of December 31st $ 276.4 $ (7.3) $ 266.6 $ (2.3) $ 254.0 $ (19.8) $ 291.6 $ (4.3) Actuarial Gains and Losses: For the year ended December 31, 2022, actuarial gains were primarily attributable to an increase in the discount rate, which resulted in a decrease to the Eversource PBOP projected benefit obligation of $180.1 million. For the year ended December 31, 2021, actuarial gains were primarily attributable to an increase in the discount rate, which resulted in a decrease to the Eversource PBOP liability of $29.8 million, and by changes in our retirement assumptions. A reconciliation of the prepaid assets and liabilities within the Eversource Pension, SERP and PBOP Plans’ funded status to the balance sheets is as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Prepaid Pension $ 756.7 $ 147.9 $ 310.2 $ 66.4 $ — $ 0.4 $ 149.8 $ — Prepaid PBOP 288.8 — 266.6 — 272.0 — 291.6 — Prepaid Pension and PBOP $ 1,045.5 $ 147.9 $ 576.8 $ 66.4 $ 272.0 $ 0.4 $ 441.4 $ — Accrued Pension $ 3.7 $ — $ — $ — $ 58.1 $ — $ — $ 20.6 Accrued SERP 166.7 5.9 1.8 4.6 176.1 7.5 2.2 5.8 Accrued PBOP 12.4 7.3 — 2.3 18.0 19.8 — 4.3 Less: Accrued SERP - current portion (47.3) (0.3) (0.2) (0.4) (9.7) (0.5) (0.2) (0.5) Accrued Pension, SERP and PBOP $ 135.5 $ 12.9 $ 1.6 $ 6.5 $ 242.5 $ 26.8 $ 2.0 $ 30.2 The following actuarial assumptions were used in calculating the Pension, SERP and PBOP Plans' year end funded status: Pension and SERP PBOP As of December 31, As of December 31, 2022 2021 2022 2021 Discount Rate 5.1% — 5.2% 2.8% — 3.0% 5.2% 2.91% — 2.92% Compensation/Progression Rate 3.5% — 4.0% 3.5% — 4.0% N/A For the Eversource Service PBOP Plan, the health care cost trend rate is not applicable. For the Aquarion PBOP Plan, the health care cost trend rate for pre-65 retirees is 7 percent, with an ultimate rate of 5 percent in 2031, and for post-65 retirees, the health care trend rate and ultimate rate is 3.5 percent. Expense: Eversource charges net periodic benefit plan expense/(income) for the Pension, SERP and PBOP Plans to its subsidiaries based on the actual participant demographic data for each subsidiary's participants. The actual investment return in the trust is allocated to each of the subsidiaries annually in proportion to the investment return expected to be earned during the year. The Company utilizes the spot rate methodology to estimate the discount rate for the service and interest cost components of benefit expense, which provides a relatively precise measurement by matching projected cash flows to the corresponding spot rates on the yield curve. The components of net periodic benefit plan expense/(income) for the Pension, SERP and PBOP Plans, prior to amounts capitalized as Property, Plant and Equipment or deferred as regulatory assets/(liabilities) for future recovery or refund, are shown below. The service cost component of net periodic benefit plan expense/(income), less the capitalized portion, is included in Operations and Maintenance expense on the statements of income. The remaining components of net periodic benefit plan expense/(income), less the deferred portion, are included in Other Income, Net on the statements of income. Pension, SERP and PBOP expense reflected in the statements of cash flows for CL&P, NSTAR Electric and PSNH does not include intercompany allocations of net periodic benefit plan expense/(income), as these amounts are cash settled on a short-term basis. Pension and SERP PBOP For the Year Ended December 31, 2022 For the Year Ended December 31, 2022 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 70.1 $ 18.7 $ 13.8 $ 6.9 $ 11.6 $ 2.0 $ 2.0 $ 1.1 Interest Cost 154.5 31.3 32.8 16.9 20.2 3.7 5.3 2.2 Expected Return on Plan Assets (523.6) (106.3) (128.4) (56.1) (89.9) (11.4) (42.4) (6.7) Actuarial Loss 116.0 16.2 32.8 7.9 — — — — Prior Service Cost/(Credit) 1.4 — 0.3 — (21.7) 1.1 (17.0) 0.4 Total Net Periodic Benefit Plan Income $ (181.6) $ (40.1) $ (48.7) $ (24.4) $ (79.8) $ (4.6) $ (52.1) $ (3.0) Intercompany Income Allocations N/A $ (16.0) $ (12.4) $ (3.6) N/A $ (3.7) $ (3.6) $ (1.2) Pension and SERP PBOP For the Year Ended December 31, 2021 For the Year Ended December 31, 2021 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 85.8 $ 23.0 $ 15.8 $ 8.9 $ 13.5 $ 2.3 $ 2.4 $ 1.2 Interest Cost 130.0 27.3 26.8 14.5 17.4 3.2 4.4 1.8 Expected Return on Plan Assets (437.5) (86.8) (108.1) (47.5) (79.1) (10.3) (36.9) (6.1) Actuarial Loss 243.9 45.5 61.6 20.7 8.9 1.8 2.4 0.7 Prior Service Cost/(Credit) 1.4 — 0.3 — (21.2) 1.1 (17.0) 0.4 Total Net Periodic Benefit Plan Expense/(Income) $ 23.6 $ 9.0 $ (3.6) $ (3.4) $ (60.5) $ (1.9) $ (44.7) $ (2.0) Intercompany Expense/(Income) Allocations N/A $ 8.0 $ 8.8 $ 2.7 N/A $ (1.6) $ (1.9) $ (0.6) Pension and SERP PBOP For the Year Ended December 31, 2020 For the Year Ended December 31, 2020 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 76.2 $ 21.8 $ 15.4 $ 8.2 $ 10.2 $ 1.7 $ 2.1 $ 0.9 Interest Cost 177.8 37.3 38.6 19.4 24.6 4.4 6.6 2.8 Expected Return on Plan Assets (400.3) (79.2) (103.0) (44.7) (73.6) (9.9) (34.0) (5.7) Actuarial Loss 202.0 39.2 55.2 15.6 8.4 1.1 2.5 0.8 Prior Service Cost/(Credit) 1.2 — 0.3 — (21.2) 1.1 (17.0) 0.4 Total Net Periodic Benefit Plan Expense/(Income) $ 56.9 $ 19.1 $ 6.5 $ (1.5) $ (51.6) $ (1.6) $ (39.8) $ (0.8) Intercompany Expense/(Income) Allocations N/A $ 9.1 $ 8.9 $ 2.9 N/A $ (1.1) $ (1.4) $ (0.5) The following actuarial assumptions were used to calculate Pension, SERP and PBOP expense amounts: Pension and SERP PBOP For the Years Ended December 31, For the Years Ended December 31, 2022 2021 2020 2022 2021 2020 Discount Rate 2.2% — 3.2% 1.5% — 3.0% 2.6% — 3.5% 2.3% — 3.3% 1.8% — 3.1% 2.7% — 3.6% Expected Long-Term Rate of Return 8.25% 8.25% 8.25% 8.25% 8.25% 8.25% Compensation/Progression Rate 3.5% — 4.0% 3.5% — 4.0% 3.5% — 4.0% N/A N/A N/A For the Aquarion Pension and PBOP Plans, the expected long-term rate of return was 7 percent for the years ended December 31, 2022 and 2021. For the Aquarion PBOP Plan, the health care cost trend rate was a range of 3.5 percent to 6.5 percent for the year ended December 31, 2022 and 3.5 percent to 6.2 percent for the year ended December 31, 2021. Regulatory Assets and Accumulated Other Comprehensive Income/(Loss) Amounts: The Pension, SERP and PBOP Plans cover eligible employees, including, among others, employees of the regulated companies. The regulated companies record actuarial losses and gains and prior service costs and credits arising at the December 31st remeasurement date of the funded status of the benefit plans as a regulatory asset or regulatory liability in lieu of a charge to Accumulated Other Comprehensive Income/(Loss), reflecting ultimate recovery from customers through rates. Regulatory accounting is also applied to the portions of the Eversource Service retiree benefit costs that support the regulated companies, as these costs are also recovered from customers. Adjustments to the Pension, SERP and PBOP Plans' funded status for the unregulated companies are recorded on an after-tax basis to Accumulated Other Comprehensive Income/(Loss). For further information, see Note 2, "Regulatory Accounting," and Note 16, "Accumulated Other Comprehensive Income/(Loss)," to the financial statements. The following is a summary of the changes in plan assets and benefit obligations recognized in Regulatory Assets and Other Comprehensive Income (OCI) as well as amounts in Regulatory Assets and OCI that were reclassified as net periodic benefit expense during the years presented: Pension and SERP PBOP Regulatory Assets OCI Regulatory Assets OCI For the Years Ended December 31, For the Years Ended December 31, (Millions of Dollars) 2022 2021 2022 2021 2022 2021 2022 2021 Actuarial (Gains)/Losses Arising During the Year $ (431.6) $ (961.7) $ 4.6 $ (28.4) $ 36.8 $ (181.5) $ (0.8) $ (4.0) Actuarial Losses Reclassified as Net Periodic Benefit Expense (107.0) (231.2) (9.0) (12.7) — (8.5) — (0.4) Prior Service (Cost)/Credit Reclassified as Net Periodic (1.2) (1.3) (0.2) (0.1) 21.8 21.1 (0.1) 0.1 The following is a summary of the remaining Regulatory Assets and Accumulated Other Comprehensive Income amounts that have not been recognized as components of net periodic benefit expense as of December 31, 2022 and 2021: Regulatory Assets as of December 31, AOCI as of December 31, (Millions of Dollars) 2022 2021 2022 2021 Pension and SERP Actuarial Loss $ 888.7 $ 1,427.3 $ 61.9 $ 66.3 Prior Service Cost 4.1 5.3 0.4 0.6 PBOP Actuarial Loss $ 81.8 $ 45.0 $ 2.7 $ 3.5 Prior Service (Credit)/Cost (108.3) (130.1) 0.9 1.0 The difference between the actual return and calculated expected return on plan assets for the Pension and PBOP Plans, as well as changes in actuarial assumptions impacting the projected benefit obligation, are recorded as unamortized actuarial gains or losses arising during the year in Regulatory Assets or Accumulated Other Comprehensive Income/(Loss). Unamortized actuarial gains or losses are amortized as a component of pension and PBOP expense over the estimated average future employee service period using the corridor approach. Estimated Future Benefit Payments: The following benefit payments, which reflect expected future service, are expected to be paid by the Pension, SERP and PBOP Plans: (Millions of Dollars) 2023 2024 2025 2026 2027 2028 - 2032 Pension and SERP $ 401.4 $ 374.4 $ 380.1 $ 383.0 $ 384.1 $ 1,901.7 PBOP 57.9 57.3 56.6 55.5 54.4 253.7 Eversource Contributions: Based on the current status of the Pension Plans and federal pension funding requirements, there is no minimum funding requirement for our Eversource Service Pension Plan in 2023 and we do not expect to make pension contributions in 2023. We do not expect to make any contributions to the Eversource Service PBOP Plan in 2023. Eversource currently estimates contributing $5.0 million and $2.9 million to the Aquarion Pension and PBOP Plans, respectively, in 2023. Fair Value of Pension and PBOP Plan Assets: Pension and PBOP funds are held in external trusts. Trust assets, including accumulated earnings, must be used exclusively for Pension and PBOP payments. Eversource's investment strategy for its Pension and PBOP Plans is to maximize the long-term rates of return on these plans' assets within an acceptable level of risk. The investment strategy for each asset category includes a diversification of asset types, fund strategies and fund managers and it establishes target asset allocations that are routinely reviewed and periodically rebalanced. PBOP assets are comprised of assets held in the PBOP Plan trust, as well as specific assets within the Pension Plan trust (401(h) assets). The investment policy and strategy of the 401(h) assets is consistent with that of the defined benefit pension plan. Eversource's expected long-term rates of return on Pension and PBOP Plan assets are based on target asset allocation assumptions and related expected long-term rates of return. In developing its expected long-term rate of return assumptions for the Pension and PBOP Plans, Eversource evaluated input from consultants, as well as long-term inflation assumptions and historical returns. Management has assumed long-term rates of return of 8.25 percent for the Eversource Service Pension and PBOP Plan assets and a 7 percent long-term rate of return for the Aquarion Plans to estimate its 2023 Pension and PBOP costs. These long-term rates of return are based on the assumed rates of return for the target asset allocations as follows: As of December 31, 2022 2021 Eversource Pension Plan and PBOP Plan Eversource Pension Plan and PBOP Plan Target Asset Allocation Assumed Rate of Return Target Asset Allocation Assumed Rate of Return Equity Securities: United States 15.0 % 8.5 % 15.0 % 8.5 % Global 10.0 % 8.75 % 10.0 % 8.75 % Non-United States 8.0 % 8.5 % 8.0 % 8.5 % Emerging Markets 4.0 % 10.0 % 4.0 % 10.0 % Debt Securities: Fixed Income 13.0 % 4.0 % 13.0 % 4.0 % Public High Yield Fixed Income 4.0 % 6.5 % 4.0 % 6.5 % Private Debt 13.0 % 9.0 % 13.0 % 9.0 % Private Equity 18.0 % 12.0 % 18.0 % 12.0 % Real Assets 15.0 % 7.5 % 15.0 % 7.5 % The following table presents, by asset category, the Pension and PBOP Plan assets recorded at fair value on a recurring basis by the level in which they are classified within the fair value hierarchy: Pension Plan Fair Value Measurements as of December 31, (Millions of Dollars) 2022 2021 Asset Category: Level 1 Level 2 Uncategorized Total Level 1 Level 2 Uncategorized Total Equity Securities $ 407.7 $ — $ 1,102.2 $ 1,509.9 $ 722.5 $ — $ 1,385.2 $ 2,107.7 Fixed Income (1) 277.1 78.5 1,598.8 1,954.4 139.6 233.8 1,689.1 2,062.5 Private Equity — — 1,684.9 1,684.9 — — 1,702.7 1,702.7 Real Assets 181.8 — 731.0 912.8 218.3 — 702.8 921.1 Total $ 866.6 $ 78.5 $ 5,116.9 $ 6,062.0 $ 1,080.4 $ 233.8 $ 5,479.8 $ 6,794.0 Less: 401(h) PBOP Assets (2) (255.6) (298.5) Total Pension Assets $ 5,806.4 $ 6,495.5 PBOP Plan Fair Value Measurements as of December 31, (Millions of Dollars) 2022 2021 Asset Category: Level 1 Level 2 Uncategorized Total Level 1 Level 2 Uncategorized Total Equity Securities $ 153.2 $ — $ 183.5 $ 336.7 $ 191.4 $ — $ 248.3 $ 439.7 Fixed Income 18.2 40.2 141.1 199.5 49.7 45.2 125.5 220.4 Private Equity — — 70.9 70.9 — — 58.7 58.7 Real Assets 71.2 — 36.2 107.4 90.0 — 31.0 121.0 Total $ 242.6 $ 40.2 $ 431.7 $ 714.5 $ 331.1 $ 45.2 $ 463.5 $ 839.8 Add: 401(h) PBOP Assets (2) 255.6 298.5 Total PBOP Assets $ 970.1 $ 1,138.3 (1) Fixed Income investments classified as Level 1 as of December 31, 2022 include pending redemption settlements of $138 million. (2) The assets of the Pension Plan include a 401(h) account that has been allocated to provide health and welfare postretirement benefits under the PBOP Plan. The Company values assets based on observable inputs when available. Equity securities, exchange traded funds and futures contracts classified as Level 1 in the fair value hierarchy are priced based on the closing price on the primary exchange as of the balance sheet date. Fixed income securities, such as government issued securities and corporate bonds, are included in Level 2 and are valued using pricing models, quoted prices of securities with similar characteristics or discounted cash flows. The pricing models utilize observable inputs such as recent trades for the same or similar instruments, yield curves, discount margins and bond structures. Swaps are valued using pricing models that incorporate interest rates and equity and fixed income index closing prices to determine a net present value of the cash flows. Eversource maintains defined contribution plans on behalf of eligible participants. The Eversource 401k Plan provides for employee and employer contributions up to statutory limits. For eligible employees, the Eversource 401k Plan provides employer matching contributions of either 100 percent up to a maximum of three percent of eligible compensation or 50 percent up to a maximum of eight percent of eligible compensation. The Eversource 401k Plan also contains a K-Vantage feature for the benefit of eligible participants, which provides an additional annual employer contribution based on age and years of service. K-Vantage participants are not eligible to actively participate in the Eversource Pension Plan. The total Eversource 401k Plan employer matching contributions, including the K-Vantage contributions, were as follows: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2022 $ 59.9 $ 7.7 $ 12.8 $ 4.8 2021 55.5 7.0 12.2 4.3 2020 49.4 6.6 11.8 4.1 Share-based compensation awards are recorded using a fair-value based method at the date of grant. Eversource, CL&P, NSTAR Electric and PSNH record compensation expense related to these awards, as applicable, for shares issued to their respective employees and officers, as well as for the allocation of costs associated with shares issued to Eversource's service company employees and officers that support CL&P, NSTAR Electric and PSNH. Eversource Incentive Plans: Eversource maintains long-term equity-based incentive plans in which Eversource, CL&P, NSTAR Electric and PSNH employees, officers and board members are eligible to participate. The incentive plans authorize Eversource to grant up to 3,200,000 new shares for various types of awards, including RSUs and performance shares, to eligible employees, officers, and board members. As of December 31, 2022 and 2021, Eversource had 903,183 and 2,430,716 common shares, respectively, available for issuance under these plans. Eversource accounts for its various share-based plans as follows: • RSUs - Eversource records compensation expense, net of estimated forfeitures, on a straight-line basis over the requisite service period based upon the fair value of Eversource's common shares at the date of grant. The par value of RSUs is reclassified to Common Stock from Capital Surplus, Paid In as RSUs become issued as common shares. • Performance Shares - Eversource records compensation expense, net of estimated forfeitures, over the requisite service period. Performance shares vest based upon the extent to which Company goals are achieved. Vesting of outstanding performance shares is based upon the Company's EPS growth over the requisite service period and level of payout is determined based on the total shareholder return as compared to the Edison Electric Institute (EEI) Index during the requisite service period. The fair value of performance shares is determined at the date of grant using a lattice model. Compensation expense is subject to volatility until payout is established. RSUs: Eversource granted RSUs under the annual long-term incentive programs that are subject to three-year graded vesting schedules for employees, and one-year graded vesting schedules, or immediate vesting, for board members. RSUs are paid in shares, reduced by amounts sufficient to satisfy withholdings for income taxes, subsequent to vesting. A summary of RSU transactions is as follows: RSUs Weighted Average Outstanding as of December 31, 2021 594,623 $ 65.70 Granted 218,005 $ 85.96 Shares Issued (174,633) $ 79.89 Forfeited (8,261) $ 85.87 Outstanding as of December 31, 2022 629,734 $ 68.52 The weighted average grant-date fair value of RSUs granted for the years ended December 31, 2022, 2021 and 2020 was $85.96, $81.89 and $88.23, respectively. As of December 31, 2022 and 2021, the number and weighted average grant-date fair value of unvested RSUs was 300,592 and $87.21 per share, and 297,270 and $83.39 per share, respectively. During 2022, there were 184,540 RSUs at a weighted average grant-date fair value of $81.07 per share that vested during the year and were either paid or deferred. As of December 31, 2022, 329,142 RSUs were fully vested and deferred and an additional 285,562 are expected to vest. Performance Shares: Eversource granted performance shares under the annual long-term incentive programs that vest based upon the extent to which Company goals are achieved at the end of three-year performance measurement periods. Performance shares are paid in shares, after the performance measurement period. A summary of performance share transactions is as follows: Performance Shares Weighted Average Outstanding as of December 31, 2021 464,507 $ 80.54 Granted 337,406 $ 83.34 Shares Issued (248,981) $ 68.96 Forfeited (5,642) $ 85.28 Outstanding as of December 31, 2022 547,290 $ 87.49 The weighted average grant-date fair value of performance shares granted for the years ended December 31, 2022, 2021 and 2020 was $83.34, $76.08 and $75.36, respectively. As of December 31, 2022 and 2021, the number and weighted average grant-date fair value of unvested performance shares was 457,069 and $88.43 per share, and 436,957 and $81.41 per share, respectively. During 2022, there were 311,553 performance shares at a weighted average grant-date fair value of $73.15 per share that vested during the year and were either paid or deferred. As of December 31, 2022, 90,221 performance shares were fully vested and deferred. Compensation Expense: The total compensation expense and associated future income tax benefits recognized by Eversource, CL&P, NSTAR Electric and PSNH for share-based compensation awards were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Compensation Expense $ 33.4 $ 28.2 $ 33.9 Future Income Tax Benefit 8.7 7.3 8.9 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Compensation Expense $ 10.0 $ 10.7 $ 3.6 $ 8.8 $ 9.0 $ 3.0 $ 10.9 $ 11.3 $ 3.6 Future Income Tax Benefit 2.6 2.8 0.9 2.3 2.3 0.8 2.9 3.0 1.0 As of December 31, 2022, there was $24.5 million of total unrecognized compensation expense related to nonvested share-based awards for Eversource, including $4.0 million for CL&P, $6.9 million for NSTAR Electric, and $1.4 million for PSNH. This cost is expected to be recognized ratably over a weighted-average period of 1.77 years for Eversource and 1.78 years for CL&P, NSTAR Electric and PSNH. An income tax rate of 26 percent was used to estimate the tax effect on total share-based payments determined under the fair-value based method for all awards. The Company issues treasury shares to settle fully vested RSUs and performance shares under the Company's incentive plans. For the years ended December 31, 2022, 2021 and 2020, excess tax benefits associated with the distribution of stock compensation awards reduced income tax expense by $2.1 million, $4.0 million, and $6.6 million, respectively, which increased cash flows from operating activities on the statements of cash flows. Eversource provides retirement and other benefits for certain current and past company officers. These benefits are accounted for on an accrual basis and expensed over a period equal to the service lives of the employees. The actuarially-determined liability for these benefits is included in Other Current and Long-Term Liabilities on the balance sheets. The related expense, which includes the allocation of expense associated with Eversource's service company officers that support CL&P, NSTAR Electric and PSNH, is included in Operations and Maintenance Expense on the income statements. The liability and expense amounts are as follows: Eversource (Millions of Dollars) As of and For the Years Ended December 31, 2022 2021 2020 Actuarially-Determined Liability $ 43.4 $ 42.8 $ 45.7 Other Retirement Benefits Expense (1) 10.9 2.2 3.3 As of and For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH Actuarially-Determined Liability $ 0.2 $ 0.1 $ 1.3 $ 0.2 $ 0.1 $ 1.5 $ 0.2 $ 0.1 $ 1.7 Other Retirement Benefits Expense (1) 4.0 3.7 1.3 0.7 0.7 0.3 1.2 1.1 0.5 (1) Other Retirement Benefits Expense in 2022 includes a one-time special retirement benefit payable of $9.2 million.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The components of income tax expense are as follows: Eversource (Millions of Dollars) For the Years Ended December 31, 2022 2021 2020 Current Income Taxes: Federal $ 95.8 $ 21.5 $ 73.6 State 13.6 (21.6) 19.1 Total Current 109.4 (0.1) 92.7 Deferred Income Taxes, Net: Federal 198.8 199.7 173.5 State 148.0 147.4 83.7 Total Deferred 346.8 347.1 257.2 Investment Tax Credits, Net (2.6) (2.8) (3.7) Income Tax Expense $ 453.6 $ 344.2 $ 346.2 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH Current Income Taxes: Federal $ 106.2 $ 55.0 $ 29.6 $ 15.0 $ 52.3 $ 43.1 $ 12.0 $ 53.9 $ 20.6 State 20.1 8.7 5.9 (7.0) 6.2 10.8 (6.1) 6.9 3.8 Total Current 126.3 63.7 35.5 8.0 58.5 53.9 5.9 60.8 24.4 Deferred Income Taxes, Net: Federal 17.2 35.6 5.9 76.3 16.3 (14.9) 101.1 33.8 (1.3) State 28.2 42.4 9.9 47.6 41.2 0.4 43.4 38.8 8.6 Total Deferred 45.4 78.0 15.8 123.9 57.5 (14.5) 144.5 72.6 7.3 Investment Tax Credits, Net (0.5) (1.7) — (0.6) (1.7) — (0.7) (2.6) — Income Tax Expense $ 171.2 $ 140.0 $ 51.3 $ 131.3 $ 114.3 $ 39.4 $ 149.7 $ 130.8 $ 31.7 A reconciliation between income tax expense and the expected tax expense at the statutory rate is as follows: Eversource (Millions of Dollars, except percentages) For the Years Ended December 31, 2022 2021 2020 Income Before Income Tax Expense $ 1,866.0 $ 1,572.3 $ 1,558.9 Statutory Federal Income Tax Expense at 21% 391.9 330.2 327.4 Tax Effect of Differences: Depreciation (17.1) (18.1) (11.1) Investment Tax Credit Amortization (2.6) (2.8) (3.7) State Income Taxes, Net of Federal Impact 75.9 54.4 44.9 Dividends on ESOP (5.1) (5.1) (5.1) Tax Asset Valuation Allowance/Reserve Adjustments 51.6 44.6 33.4 Excess Stock Benefit (2.1) (4.0) (6.6) EDIT Amortization (49.1) (69.1) (48.7) Other, Net 10.2 14.1 15.7 Income Tax Expense $ 453.6 $ 344.2 $ 346.2 Effective Tax Rate 24.3 % 21.9 % 22.2 % For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars, except percentages) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Income Before Income Tax Expense $ 704.1 $ 632.4 $ 222.9 $ 533.0 $ 590.9 $ 189.8 $ 607.6 $ 575.8 $ 179.0 Statutory Federal Income Tax Expense at 21% 147.9 132.8 46.8 111.9 124.1 39.9 127.6 120.9 37.6 Tax Effect of Differences: Depreciation (3.7) (4.2) 0.9 (6.4) (3.4) (0.2) 0.4 (3.7) (1.4) Investment Tax Credit Amortization (0.5) (1.7) — (0.6) (1.7) — (0.7) (2.6) — State Income Taxes, Net of Federal Impact (6.6) 40.3 12.5 (4.6) 37.5 8.9 (1.2) 36.0 9.8 Tax Asset Valuation 44.7 — — 36.7 — — 30.7 — — Excess Stock Benefit (0.7) (0.8) (0.3) (1.5) (1.4) (0.5) (2.3) (2.3) (0.8) EDIT Amortization (9.2) (29.2) (7.7) (9.8) (43.2) (10.5) (9.0) (20.4) (15.4) Other, Net (0.7) 2.8 (0.9) 5.6 2.4 1.8 4.2 2.9 1.9 Income Tax Expense $ 171.2 $ 140.0 $ 51.3 $ 131.3 $ 114.3 $ 39.4 $ 149.7 $ 130.8 $ 31.7 Effective Tax Rate 24.3 % 22.1 % 23.0 % 24.6 % 19.3 % 20.8 % 24.6 % 22.7 % 17.7 % Eversource, CL&P, NSTAR Electric and PSNH file a consolidated federal income tax return and unitary, combined and separate state income tax returns. These entities are also parties to a tax allocation agreement under which taxable subsidiaries do not pay any more taxes than they would have otherwise paid had they filed a separate company tax return, and subsidiaries generating tax losses, if any, are paid for their losses when utilized. Deferred tax assets and liabilities are recognized for the future tax effects of temporary differences between the carrying amounts and the tax basis of assets and liabilities. The tax effect of temporary differences is accounted for in accordance with the rate-making treatment of the applicable regulatory commissions and relevant accounting authoritative literature. The tax effects of temporary differences that give rise to the net accumulated deferred income tax obligations are as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Deferred Tax Assets: Employee Benefits $ 228.9 $ 25.3 $ 57.4 $ 11.6 $ 270.8 $ 23.9 $ 40.3 $ 14.1 Derivative Liabilities 53.8 53.8 — — 76.8 76.8 — — Regulatory Deferrals - Liabilities 529.5 146.6 285.7 42.1 390.7 90.9 215.4 24.3 Allowance for Uncollectible Accounts 125.5 60.5 20.7 7.9 104.1 48.8 21.5 6.2 Tax Effect - Tax Regulatory Liabilities 762.9 324.6 241.8 97.8 783.4 328.2 254.3 100.9 Net Operating Loss Carryforwards 16.7 — — — 7.5 — — — Purchase Accounting Adjustment 62.0 — — — 67.2 — — — Other 176.6 109.5 20.5 21.3 196.6 103.9 21.7 22.9 Total Deferred Tax Assets 1,955.9 720.3 626.1 180.7 1,897.1 672.5 553.2 168.4 Less: Valuation Allowance 82.8 63.3 — — 61.5 44.5 — — Net Deferred Tax Assets $ 1,873.1 $ 657.0 $ 626.1 $ 180.7 $ 1,835.6 $ 628.0 $ 553.2 $ 168.4 Deferred Tax Liabilities: Accelerated Depreciation and Other $ 4,793.7 $ 1,602.0 $ 1,643.7 $ 523.8 $ 4,426.0 $ 1,509.5 $ 1,553.7 $ 482.9 Property Tax Accruals 95.3 40.7 41.3 6.7 88.1 40.5 33.7 6.3 Regulatory Amounts: Regulatory Deferrals - Assets 1,251.9 406.4 407.9 165.2 1,260.3 438.3 337.6 198.4 Tax Effect - Tax Regulatory Assets 271.7 185.6 10.7 7.9 257.8 181.4 10.9 8.3 Goodwill-related Regulatory Asset - 1999 Merger 76.8 — 65.9 — 81.4 — 69.9 — Employee Benefits 305.5 45.0 140.8 18.7 174.7 3.5 107.1 0.7 Derivative Assets 10.5 10.5 — — 14.9 14.9 — — Other 135.6 6.8 16.7 21.2 129.5 2.0 19.8 9.8 Total Deferred Tax Liabilities $ 6,941.0 $ 2,297.0 $ 2,327.0 $ 743.5 $ 6,432.7 $ 2,190.1 $ 2,132.7 $ 706.4 2022 Federal Legislation: On August 16, 2022, the Inflation Reduction Act of 2022 (IRA) was signed into law. This is a broad package of legislation that includes incentives and support for clean energy resource development. Most notable for Eversource, the investment tax credit (ITC) on offshore wind projects increases from 30 percent to 40 percent if certain requirements for labor and domestic content are met. The act also re-establishes the production tax credit for solar and wind energy projects, gives increased credit for projects in certain communities, and sets credits for qualifying clean energy generation and energy storage projects. The tax provisions of the IRA provide additional incentives for offshore wind projects and could reduce retail electricity costs for our customers related to those clean energy investments. The IRA includes other tax provisions focused on implementing a 15 percent minimum tax on adjusted financial statement income and a one percent excise tax on corporate share repurchases. The Department of Treasury and the Internal Revenue Service issued limited guidance in the fourth quarter; however, they are expected to issue additional needed guidance with respect to the application of the newly enacted IRA provisions in the future. We will continue to monitor and evaluate impacts on our consolidated financial statements. We currently do not expect the alternative minimum tax change to have a material impact on our earnings, financial condition or cash flows. 2021 Federal Legislation: On November 5, 2021, Congress passed the Infrastructure Investment and Jobs Act. The Act provided spending of more than $500 billion on roads, highways, bridges, public transit, and utilities. For water and sewer utilities, the Act restored the exclusion from a corporation’s income for contributions in aid of construction where the corporation is a water or sewer utility eliminated by the Tax Cuts and Jobs Act of 2017. Under the Act, a regulated public utility that provides water or sewage disposal services can treat money or property received from any person as a tax-free contribution to capital if it meets certain criteria for contributions made after 2020. The Act did not have a material impact on Eversource in 2021. Carryforwards: The following table provides the amounts and expiration dates of state tax credit and loss carryforwards and federal tax credit and net operating loss carryforwards: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Expiration Range Eversource CL&P NSTAR PSNH Expiration Range State Net Operating Loss $ 288.1 $ — $ — $ — 2022 - 2041 $ 138.3 $ — $ — $ — 2021 - 2040 State Tax Credit 204.5 137.7 — — 2022 - 2027 197.7 137.0 — — 2021 - 2026 State Charitable Contribution 20.1 — — — 2022 - 2026 23.7 — — — 2021 - 2025 In 2022, the Company increased its valuation allowance reserve for state credits by $21.3 million ($18.8 million for CL&P), net of tax, to reflect an update for expiring tax credits. In 2021 , the Company increased its valuation allowance reserve for state credits by $13.0 million ($10.8 million for CL&P), net of tax, to reflect an update for expiring tax credits. For 2022 and 2021, state credit and state loss carryforwards have been partially reserved by a valuation allowance of $82.8 million and $61.5 million (net of tax), respectively. Unrecognized Tax Benefits: A reconciliation of the activity in unrecognized tax benefits, all of which would impact the effective tax rate if recognized, is as follows: (Millions of Dollars) Eversource CL&P Balance as of January 1, 2020 $ 55.0 $ 23.1 Gross Increases - Current Year 11.9 4.6 Gross Increases - Prior Year 1.4 0.7 Lapse of Statute of Limitations (6.5) (2.6) Balance as of December 31, 2020 61.8 25.8 Gross Increases - Current Year 11.3 3.8 Gross Decreases - Prior Year (0.3) (0.6) Lapse of Statute of Limitations (7.0) (2.8) Balance as of December 31, 2021 65.8 26.2 Gross Increases - Current Year 11.5 3.5 Gross Decreases - Prior Year (2.4) (0.9) Lapse of Statute of Limitations (7.8) (3.3) Balance as of December 31, 2022 $ 67.1 $ 25.5 Interest and Penalties: Interest on uncertain tax positions is recorded and generally classified as a component of Other Interest Expense on the statements of income. However, when resolution of uncertainties results in the Company receiving interest income, any related interest benefit is recorded in Other Income, Net on the statements of income. No penalties have been recorded. There has been no interest expense or income recognized on uncertain tax positions for the years ended December 31, 2022, 2021 or 2020. The accrued interest payable was $0.1 million as of both December 31, 2022 and 2021. Tax Positions: During 2022 and 2021, Eversource did not resolve any of its uncertain tax positions. Open Tax Years: The following table summarizes Eversource, CL&P, NSTAR Electric, and PSNH's tax years that remain subject to examination by major tax jurisdictions as of December 31, 2022: Description Tax Years Federal 2022 Connecticut 2019 - 2022 Massachusetts 2019 - 2022 New Hampshire 2019 - 2022 Eversource does not estimate to have an earnings impact related to unrecognized tax benefits during the next twelve months.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES A. Environmental Matters Eversource, CL&P, NSTAR Electric and PSNH are subject to environmental laws and regulations intended to mitigate or remove the effect of past operations and improve or maintain the quality of the environment. These laws and regulations require the removal or the remedy of the effect on the environment of the disposal or release of certain specified hazardous substances at current and former operating sites. Eversource, CL&P, NSTAR Electric and PSNH have an active environmental auditing and training program and each believes it is substantially in compliance with all enacted laws and regulations. Environmental reserves are accrued when assessments indicate it is probable that a liability has been incurred and an amount can be reasonably estimated. The approach used estimates the liability based on the most likely action plan from a variety of available remediation options, including no action required or several different remedies ranging from establishing institutional controls to full site remediation and monitoring. These liabilities are estimated on an undiscounted basis and do not assume that the amounts are recoverable from insurance companies or other third parties. The environmental reserves include sites at different stages of discovery and remediation and do not include any unasserted claims. These reserve estimates are subjective in nature as they take into consideration several different remediation options at each specific site. The reliability and precision of these estimates can be affected by several factors, including new information concerning either the level of contamination at the site, the extent of Eversource's, CL&P's, NSTAR Electric's and PSNH's responsibility for remediation or the extent of remediation required, recently enacted laws and regulations or changes in cost estimates due to certain economic factors. It is possible that new information or future developments could require a reassessment of the potential exposure to required environmental remediation. As this information becomes available, management will continue to assess the potential exposure and adjust the reserves accordingly. The amounts recorded as environmental reserves are included in Other Current Liabilities and Other Long-Term Liabilities on the balance sheets and represent management's best estimate of the liability for environmental costs, and take into consideration site assessment, remediation and long-term monitoring costs. The environmental reserves also take into account recurring costs of managing hazardous substances and pollutants, mandated expenditures to remediate contaminated sites and any other infrequent and non-recurring clean-up costs. A reconciliation of the activity in the environmental reserves is as follows: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Balance as of January 1, 2021 $ 102.4 $ 12.3 $ 4.7 $ 7.1 Additions 23.4 4.4 — — Payments/Reductions (10.4) (2.8) (1.4) (0.8) Balance as of December 31, 2021 115.4 13.9 3.3 6.3 Additions 12.6 0.9 0.4 0.5 Payments/Reductions (5.4) (0.9) (0.3) (0.7) Balance as of December 31, 2022 $ 122.6 $ 13.9 $ 3.4 $ 6.1 The number of environmental sites for which remediation or long-term monitoring, preliminary site work or site assessment is being performed are as follows: Eversource CL&P NSTAR Electric PSNH 2022 59 13 10 8 2021 61 14 11 9 The increase in the reserve balance was due primarily to changes in cost estimates at certain MGP sites at our natural gas business segment, which we now know will require additional remediation. Included in the number of sites and reserve amounts above are former MGP sites that were operated several decades ago and manufactured natural gas from coal and other processes, which resulted in certain by-products remaining in the environment that may pose a potential risk to human health and the environment, for which Eversource may have potential liability. The reserve balances related to these former MGP sites were $112.6 million and $105.6 million as of December 31, 2022 and 2021, respectively, and related primarily to the natural gas business segment. As of December 31, 2022, for 15 environmental sites (7 for CL&P and 1 for NSTAR Electric) that are included in the Company's reserve for environmental costs, management cannot reasonably estimate the exposure to loss in excess of the reserve, or range of loss, as these sites are under investigation and/or there is significant uncertainty as to what remedial actions, if any, the Company may be required to undertake. As of December 31, 2022, $25.8 million (including $4.4 million for CL&P and $0.1 million for NSTAR Electric) had been accrued as a liability for these sites. As of December 31, 2022, for 7 environmental sites (1 for CL&P) that are included in the Company's reserve for environmental costs, the information known and the nature of the remediation options allow for the Company to estimate the range of losses for environmental costs. As of December 31, 2022, $29.9 million (including $0.6 million for CL&P) has been accrued as a liability for these sites, which represents the low end of the range of the liabilities for environmental costs. Management believes that additional losses of up to approximately $17 million ($0.3 million at CL&P) may be incurred in executing current remediation plans for these sites. As of December 31, 2022, for the remaining 37 environmental sites (including 5 for CL&P, 9 for NSTAR Electric and 8 for PSNH) that are included in the Company's reserve for environmental costs, the $66.9 million accrual (including $8.9 million for CL&P, $3.3 million for NSTAR Electric and $6.1 million for PSNH) represents management's best estimate of the probable liability and no additional loss is estimable at this time. Estimated Future Annual Costs: The estimated future annual costs of significant executed, non-cancelable, long-term contractual arrangements in effect as of December 31, 2022 are as follows: Eversource (Millions of Dollars) 2023 2024 2025 2026 2027 Thereafter Total Renewable Energy Purchase Contracts $ 751.8 $ 952.6 $ 954.8 $ 983.0 $ 998.5 $ 8,141.1 $ 12,781.8 Natural Gas Procurement 447.1 419.4 340.9 298.5 269.4 1,450.6 3,225.9 Purchased Power and Capacity 87.6 86.8 75.2 2.9 2.7 7.2 262.4 Peaker CfDs 20.3 21.1 17.9 16.0 11.4 64.4 151.1 Transmission Support Commitments 17.8 20.7 22.6 22.6 22.6 22.6 128.9 Total $ 1,324.6 $ 1,500.6 $ 1,411.4 $ 1,323.0 $ 1,304.6 $ 9,685.9 $ 16,550.1 CL&P (Millions of Dollars) 2023 2024 2025 2026 2027 Thereafter Total Renewable Energy Purchase Contracts $ 594.8 $ 609.1 $ 610.2 $ 607.6 $ 609.0 $ 2,253.1 $ 5,283.8 Purchased Power and Capacity 83.5 83.9 72.4 0.1 — — 239.9 Peaker CfDs 20.3 21.1 17.9 16.0 11.4 64.4 151.1 Transmission Support Commitments 7.0 8.2 8.9 8.9 8.9 8.9 50.8 Total $ 705.6 $ 722.3 $ 709.4 $ 632.6 $ 629.3 $ 2,326.4 $ 5,725.6 NSTAR Electric (Millions of Dollars) 2023 2024 2025 2026 2027 Thereafter Total Renewable Energy Purchase Contracts $ 79.2 $ 270.0 $ 316.5 $ 322.9 $ 328.6 $ 5,519.8 $ 6,837.0 Purchased Power and Capacity 2.9 2.9 2.8 2.8 2.7 7.2 21.3 Transmission Support Commitments 7.0 8.1 8.9 8.9 8.9 8.9 50.7 Total $ 89.1 $ 281.0 $ 328.2 $ 334.6 $ 340.2 $ 5,535.9 $ 6,909.0 PSNH (Millions of Dollars) 2023 2024 2025 2026 2027 Thereafter Total Renewable Energy Purchase Contracts $ 77.8 $ 73.5 $ 28.1 $ 52.5 $ 60.9 $ 368.2 $ 661.0 Purchased Power and Capacity 1.2 — — — — — 1.2 Transmission Support Commitments 3.8 4.4 4.8 4.8 4.8 4.8 27.4 Total $ 82.8 $ 77.9 $ 32.9 $ 57.3 $ 65.7 $ 373.0 $ 689.6 Renewable Energy Purchase Contracts: Renewable energy purchase contracts include non-cancellable commitments under contracts of CL&P, NSTAR Electric and PSNH for the purchase of energy and capacity from renewable energy facilities. Such contracts extend through 2043 for CL&P, 2044 for NSTAR Electric and 2033 for PSNH. Renewable Energy and Purchase Contracts includes long-term commitments of NSTAR Electric pertaining to the Vineyard Wind LLC contract awarded under the Massachusetts Clean Energy 83C procurement solicitation. NSTAR Electric, along with other Massachusetts distribution companies, entered into 20-year contracts to purchase electricity generated by this 800 megawatt offshore wind project. Construction on the Vineyard Wind project commenced in 2022. Estimated energy costs under this contract are expected to begin when the facilities are in service in 2024 and range between $240 million and $375 million per year und er NSTAR Electric’s 20-year contract, totaling approximately $6.0 billion. As required by 2018 regulation, CL&P and UI each entered into PURA-approved ten-year contracts in 2019 to purchase a combined total of approximately 9 million MWh annually from the Millstone Nuclear Power Station generation facility, which represents a combined amount of approximately 50 percent of the facility's output (approximately 40 percent by CL&P). The Millstone Nuclear Power Station has a 2,112 MW nameplate capacity. Energy deliveries and payments under these contracts began in 2019. Also as required by 2018 regulation, CL&P and UI each entered into PURA-approved eight-year contracts in 2019 to purchase a combined amount of approximately 18 percent of the Seabrook Nuclear Power Plant’s output (approximately 15 percent by CL&P) beginning January 1, 2022. The Seabrook Nuclear Power Plant has an approximate 1,250 MW nameplate capacity. The total estimated remaining future cost of the Millstone Nuclear Power Station and Seabrook Nuclear Power Plant energy purchase contracts are $2.9 billion and are reflected in the table above. CL&P sells the energy purchased under these contracts into the market and uses the proceeds from these energy sales to offset the contract costs. As the net costs under these contracts are recovered from customers in future rates, the contracts do not have an impact on the net income of CL&P. These contracts do not meet the definition of a derivative, and accordingly, the costs of these contracts are being accounted for as incurred. Excluded from the table above are long-term commitments of NSTAR Electric pertaining to the Massachusetts Clean Energy 83D contract, for which construction was suspended prior to December 31, 2021. Should the project attain feasibility and construction recommence, the estimated costs under the contract may potentially begin in 2023 and range between $150 million and $415 million per year under a 20-year contract, totaling approximately $6.7 billion. The contractual obligations table above does not include long-term commitments signed by CL&P and NSTAR Electric, as required by the PURA and DPU, respectively, for the purchase of renewable energy and related products that are contingent on the future construction of energy facilities. Natural Gas Procurement: Eversource's natural gas distribution businesses have long-term contracts for the purchase, transportation and storage of natural gas as part of its portfolio of supplies, which extend through 2045. Purchased Power and Capacity: These contracts include capacity CfDs of CL&P through 2026, and various IPP contracts or purchase obligations for electricity which extend through 2024 for CL&P, 2031 for NSTAR Electric and 2023 for PSNH. As required by regulation, CL&P, along with UI, has capacity-related contracts with generation facilities. CL&P has a sharing agreement with UI, with 80 percent of the costs or benefits of each contract borne by or allocated to CL&P and 20 percent borne by or allocated to UI. The combined capacities of these contracts as of December 31, 2022 and 2021 were 674 MW and 675 MW, respectively. The capacity contracts extend through 2026 and obligate both CL&P and UI to make or receive payments on a monthly basis to or from the generation facilities based on the difference between a set capacity price and the capacity market price received in the ISO-NE capacity markets. CL&P's portion of the costs and benefits of these contracts will be paid by, or refunded to, CL&P's customers. The contractual obligations table above does not include CL&P's, NSTAR Electric's or PSNH's standard/basic service contracts for the purchase of energy supply, the amounts of which vary with customers' energy needs. Peaker CfDs: CL&P, along with UI, has three peaker CfDs for a total of approximately 500 MW of peaking capacity through 2042. CL&P has a sharing agreement with UI, whereby CL&P is responsible for 80 percent and UI for 20 percent of the net costs or benefits of these CfDs. The Peaker CfDs pay the generation facility owner the difference between capacity, forward reserve and energy market revenues and a cost-of-service payment stream for 30 years. The ultimate cost or benefit to CL&P under these contracts will depend on the costs of plant operation and the prices that the projects receive for capacity and other products in the ISO-NE markets. CL&P's portion of the amounts paid or received under the Peaker CfDs are recovered from, or refunded to, CL&P's customers. Transmission Support Commitments: Along with other New England utilities, CL&P, NSTAR Electric and PSNH entered into a series of agreements in the 1980’s to support the costs of, and receive rights to use, transmission and terminal facilities that were built to import electricity from the Hydro-Québec system in Canada. CL&P, NSTAR Electric and PSNH were obligated to pay, over a 30-year period that ended in 2020, their proportionate shares of the annual operation and maintenance expenses and capital costs of those facilities. On December 18, 2020, the parties to these agreements submitted to FERC an offer of settlement and amendments to these agreements implementing the terms of an extension for an additional 20-year period ending in 2040. On May 20, 2021, FERC approved this settlement, effective January 1, 2021. The total costs incurred under these agreements were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Renewable Energy Purchase Contracts $ 678.1 $ 609.2 $ 584.2 Natural Gas Procurement 1,042.8 712.7 453.4 Purchased Power and Capacity 61.6 56.4 62.7 Peaker CfDs 13.4 24.3 22.7 Transmission Support Commitments 12.7 15.4 22.1 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Renewable Energy Purchase Contracts $ 513.2 $ 90.8 $ 74.1 $ 457.1 $ 84.7 $ 67.4 $ 426.3 $ 88.8 $ 69.1 Purchased Power and Capacity 57.7 3.0 0.9 53.1 3.0 0.3 59.3 3.1 0.3 Peaker CfDs 13.4 — — 24.3 — — 22.7 — — Transmission Support Commitments 5.0 5.0 2.7 6.1 6.0 3.3 8.7 8.7 4.7 CL&P, NSTAR Electric and PSNH have plant closure and fuel storage cost obligations to the Yankee Companies, which have each completed the physical decommissioning of their respective nuclear power facilities and are now engaged in the long-term storage of their spent fuel. The Yankee Companies fund these costs through litigation proceeds received from the DOE and, to the extent necessary, through wholesale, FERC-approved rates charged under power purchase agreements with several New England utilities, including CL&P, NSTAR Electric and PSNH. CL&P, NSTAR Electric and PSNH, in turn recover these costs from their customers through state regulatory commission-approved retail rates. The Yankee Companies collect amounts that management believes are adequate to recover the remaining plant closure and fuel storage cost estimates for the respective plants. Management believes CL&P and NSTAR Electric will recover their shares of these obligations from their customers. PSNH has recovered its total share of these costs from its customers. Spent Nuclear Fuel Litigation: The Yankee Companies have filed complaints against the DOE in the Court of Federal Claims seeking monetary damages resulting from the DOE's failure to accept delivery of, and provide for a permanent facility to store, spent nuclear fuel pursuant to the terms of the 1983 spent fuel and high-level waste disposal contracts between the Yankee Companies and the DOE. The court previously awarded the Yankee Companies damages for Phases I, II, III and IV of litigation resulting from the DOE's failure to meet its contractual obligations. These Phases covered damages incurred in the years 1998 through 2016, and the awarded damages have been received by the Yankee Companies with certain amounts of the damages refunded to their customers. DOE Phase V Damages - On March 25, 2021, each of the Yankee Companies filed a fifth set of lawsuits against the DOE in the Court of Federal Claims resulting from the DOE's failure to begin accepting spent nuclear fuel for disposal covering the years from 2017 to 2020. The Yankee Companies filed claims seeking monetary damages totaling $120.4 million for CYAPC, YAEC and MYAPC. Pursuant to a June 2, 2022 court order, the Yankee Companies were subsequently permitted to include monetary damages relating to the year 2021 in the DOE Phase V complaint. The Yankee Companies submitted a supplemental filing to include these costs of $33.1 million on June 8, 2022. The DOE Phase V trial is expected to begin in the third quarter of 2023. D. Guarantees and Indemnifications In the normal course of business, Eversource parent provides credit assurances on behalf of its subsidiaries, including CL&P, NSTAR Electric and PSNH, in the form of guarantees. Management does not anticipate a material impact to net income or cash flows as a result of these various guarantees and indemnifications. Guarantees issued on behalf of unconsolidated entities, including equity method offshore wind investments, for which Eversource parent is the guarantor, are recorded at fair value as a liability on the balance sheet at the inception of the guarantee. Eversource regularly reviews performance risk under these guarantee arrangements, and in the event it becomes probable that Eversource parent will be required to perform under the guarantee, the amount of probable payment will be recorded. The fair value of guarantees issued on behalf of unconsolidated entities are recorded within Other Long-Term Liabilities on the balance sheet, and were $4.2 million and $7.3 million as of December 31, 2022 and 2021, respectively. The following table summarizes Eversource parent's exposure to guarantees and indemnifications of its subsidiaries and affiliates to external parties, and primarily relates to its offshore wind business: As of December 31, 2022 Company (Obligor) Description Maximum Exposure Expiration Dates North East Offshore LLC Construction-related purchase agreements with third-party contractors (1) $ 717.6 (1) Sunrise Wind LLC Construction-related purchase agreements with third-party contractors (2) 311.5 2025 - 2026 Revolution Wind, LLC Construction-related purchase agreements with third-party contractors (3) 419.1 2024 - 2027 South Fork Wind, LLC Construction-related purchase agreements with third-party contractors (4) 142.1 2023 - 2026 Eversource Investment LLC Funding and indemnification obligations of North East Offshore LLC (5) 77.0 (5) South Fork Wind, LLC Power Purchase Agreement Security (6) 7.1 (6) Sunrise Wind LLC OREC capacity production (7) 2.2 (7) Bay State Wind LLC Real estate purchase 2.5 2023 South Fork Wind, LLC Transmission interconnection 1.2 — Eversource Investment LLC Letters of Credit (8) 4.3 — Various Surety bonds (9) 35.7 2023 Eversource Service Lease payments for real estate 0.5 2024 (1) Eversource parent issued guarantees on behalf of its 50 percent-owned affiliate, North East Offshore LLC (NEO), under which Eversource parent agreed to guarantee 50 percent of NEO’s performance of obligations under certain purchase agreements with third-party contractors, in an aggregate amount not to exceed $1.3 billion with an expiration date in 2025. Eversource parent also issued a separate guarantee to Ørsted on behalf of NEO, under which Eversource parent agreed to guarantee 50 percent of NEO’s payment obligations under certain offshore wind project construction-related agreements with Ørsted in an aggregate amount not to exceed $62.5 million and expiring upon full performance of the guaranteed obligation. Any amounts paid under this guarantee to Ørsted will count toward, but not increase, the maximum amount of the Funding Guarantee described in Note 5, below. (2) Eversource parent issued guarantees on behalf of its 50 percent-owned affiliate, Sunrise Wind LLC, whereby Eversource parent will guarantee Sunrise Wind LLC's performance of certain obligations, in an aggregate amount not to exceed $465.8 million, in connection with construction-related purchase agreements. Eversource parent’s obligations under the guarantees expire upon the earlier of (i) dates ranging from March 2025 and April 2026 and (ii) full performance of the guaranteed obligations. (3) Eversource parent issued guarantees on behalf of its 50 percent-owned affiliate, Revolution Wind, LLC, whereby Eversource parent will guarantee Revolution Wind, LLC's performance of certain obligations, in an aggregate amount not to exceed $546.7 million, in connection with construction-related purchase agreements. Eversource parent’s obligations under the guarantees expire upon the earlier of (i) dates ranging from May 2024 and November 2027 and (ii) full performance of the guaranteed obligations. (4) Eversource parent issued guarantees on behalf of its 50 percent-owned affiliate, South Fork Wind, LLC, whereby Eversource parent will guarantee South Fork Wind, LLC's performance of certain obligations in connection with construction-related purchase agreements. Under these guarantees, Eversource parent will guarantee South Fork Wind, LLC's performance of certain obligations, in a total aggregate amount not to exceed $207.7 million. Eversource parent’s obligations under these guarantees expire upon the earlier of (i) dates ranging from June 2023 and August 2026 and (ii) full performance of the guaranteed obligations. (5) Eversource parent issued a guarantee (Funding Guarantee) on behalf of Eversource Investment LLC (EI), its wholly-owned subsidiary that holds a 50 percent ownership interest in NEO, under which Eversource parent agreed to guarantee certain funding obligations and certain indemnification payments of EI under the operating agreement of NEO, in an amount not to exceed $910 million. The guaranteed obligations include payment of EI's funding obligations during the construction phase of NEO’s underlying offshore wind projects and indemnification obligations associated with third party credit support for its investment in NEO. Eversource parent’s obligations under the Funding Guarantee expire upon the full performance of the guaranteed obligations. (6) Eversource parent issued a guarantee on behalf of its 50 percent-owned affiliate, South Fork Wind, LLC, whereby Eversource parent will guarantee South Fork Wind, LLC's performance of certain obligations, in an amount not to exceed $7.1 million, under a Power Purchase Agreement between the Long Island Power Authority and South Fork Wind, LLC (the Agreement). The guarantee expires upon the later of (i) the end of the Agreement term and (ii) full performance of the guarantee obligations. (7) Eversource parent issued a guarantee on behalf of its 50 percent-owned affiliate, Sunrise Wind LLC, whereby Eversource parent will guarantee Sunrise Wind LLC's performance of certain obligations, in an amount not to exceed $15.4 million, under the Offshore Wind Renewable Energy Certificate Purchase and Sale Agreement (the Agreement). The Agreement was executed by and between the New York State Energy Research and Development Authority (NYSERDA) and Sunrise Wind LLC. The guarantee expires upon the full performance of the guaranteed obligations. Effective January 1, 2023, exposure under the guarantee increased from $2.2 million to $11.0 million. (8) On September 16, 2020, Eversource parent entered into a guarantee on behalf of EI, which holds Eversource's investments in offshore wind-related equity method investments, under which Eversource parent would guarantee EI's obligations under a letter of credit facility with a financial institution that EI may request in an aggregate amount of up to approximately $25 million. In January 2022, Eversource parent issued two letters of credit on behalf of South Fork Wind, LLC related to future decommissioning obligations of certain onshore transmission assets totaling $4.3 million. (9) Surety bond expiration dates reflect termination dates, the majority of which will be renewed or extended. Certain surety bonds contain credit ratings triggers that would require Eversource parent to post collateral in the event that the unsecured debt credit ratings of Eversource parent are downgraded. 2023 Guaranty : In the first quarter of 2023, Eversource parent issued an additional guaranty on behalf of Sunrise Wind LLC totaling $58.1 million, whereby Eversource parent will guarantee Sunrise Wind LLC's performance of certain contractual obligations. Four separate complaints were filed at the FERC by combinations of New England state attorneys general, state regulatory commissions, consumer advocates, consumer groups, municipal parties and other parties (collectively, the Complainants). In each of the first three complaints, filed on October 1, 2011, December 27, 2012, and July 31, 2014, respectively, the Complainants challenged the NETOs' base ROE of 11.14 percent that had been utilized since 2005 and sought an order to reduce it prospectively from the date of the final FERC order and for the separate 15-month complaint periods. In the fourth complaint, filed April 29, 2016, the Complainants challenged the NETOs' base ROE billed of 10.57 percent and the maximum ROE for transmission incentive (incentive cap) of 11.74 percent, asserting that these ROEs were unjust and unreasonable. The ROE originally billed during the period October 1, 2011 (beginning of the first complaint period) through October 15, 2014 consisted of a base ROE of 11.14 percent and incentives up to 13.1 percent. On October 16, 2014, FERC issued Opinion No. 531-A and set the base ROE at 10.57 percent and the incentive cap at 11.74 percent for the first complaint period. This was also effective for all prospective billings to customers beginning October 16, 2014. This FERC order was vacated on April 14, 2017 by the U.S. Court of Appeals for the D.C. Circuit (the Court). All amounts associated with the first complaint period have been refunded, which totaled $38.9 million (pre-tax and excluding interest) at Eversource and reflected both the base ROE and incentive cap prescribed by the FERC order. The refund consisted of $22.4 million for CL&P, $13.7 million for NSTAR Electric and $2.8 million for PSNH. Eversource has recorded a reserve of $39.1 million (pre-tax and excluding interest) for the second complaint period as of both December 31, 2022 and 2021. This reserve represents the difference between the billed rates during the second complaint period and a 10.57 percent base ROE and 11.74 percent incentive cap. The reserve consisted of $21.4 million for CL&P, $14.6 million for NSTAR Electric and $3.1 million for PSNH as of both December 31, 2022 and 2021. On October 16, 2018, FERC issued an order on all four complaints describing how it intends to address the issues that were remanded by the Court. FERC proposed a new framework to determine (1) whether an existing ROE is unjust and unreasonable and, if so, (2) how to calculate a replacement ROE. Initial briefs were filed by the NETOs, Complainants and FERC Trial Staff on January 11, 2019 and reply briefs were filed on March 8, 2019. The NETOs' brief was supportive of the overall ROE methodology determined in the October 16, 2018 order provided the FERC does not change the proposed methodology or alter its implementation in a manner that has a material impact on the results. The FERC order included illustrative calculations for the first complaint using FERC's proposed frameworks with financial data from that complaint. Those illustrative calculations indicated that for the first complaint period, for the NETOs, which FERC concludes are of average financial risk, the preliminary just and reasonable base ROE is 10.41 percent and the preliminary incentive cap on total ROE is 13.08 percent. If the results of the illustrative calculations were included in a final FERC order for each of the complaint periods, then a 10.41 percent base ROE and a 13.08 percent incentive cap would not have a significant impact on our financial statements for all of the complaint periods. These preliminary calculations are not binding and do not represent what we believe to be the most likely outcome of a final FERC order. On November 21, 2019, FERC issued Opinion No. 569 affecting the two pending transmission ROE complaints against the Midcontinent ISO (MISO) transmission owners, in which FERC adopted a new methodology for determining base ROEs. Various parties sought rehearing. On December 23, 2019, the NETOs filed supplementary materials in the NETOs' four pending cases to respond to this new methodology because of the uncertainty of the applicability to the NETOs' cases. On May 21, 2020, the FERC issued its order in Opinion No. 569-A on the rehearing of the MISO transmission owners' cases, in which FERC again changed its methodology for determining the MISO transmission owners' base ROEs. On November 19, 2020, the FERC issued Opinion No. 569-B denying rehearing of Opinion No. 569-A and reaffirmed the methodology previously adopted in Opinion No. 569-A. The new methodology differs significantly from the methodology proposed by FERC in its October 16, 2018 order to determine the NETOs' base ROEs in its four pending cases. FERC Opinion Nos. 569-A and 569-B were appealed to the Court. On August 9, 2022, the Court issued its decision vacating MISO ROE FERC Opinion Nos. 569, 569-A and 569-B and remanded to FERC to reopen the proceedings. The Court found that FERC’s development of the new return methodology was arbitrary and capricious due to FERC’s failure to offer a reasonable explanation for its decision to reintroduce the risk-premium financial model in its new methodology for calculating a just and reasonable return. At this time, Eversource cannot predict how and when FERC will address the Court’s findings on the remand of the MISO FERC opinions or any potential associated impact on the NETOs’ four pending ROE complaint cases. Given the significant uncertainty regarding the applicability of the FERC opinions in the MISO transmission owners’ two complaint cases to the NETOs’ pending four complaint cases, Eversource concluded that there is no reasonable basis for a change to the reserve or recognized ROEs for any of the complaint periods at this time. As well, Eversource cannot reasonably estimate a range of loss for any of the four complaint proceedings at this time. Eversource, CL&P, NSTAR Electric and PSNH currently record revenues at the 10.57 percent base ROE and incentive cap at 11.74 percent established in the October 16, 2014 FERC order. A change of 10 basis points to the base ROE used to establish the reserves would impact Eversource’s after-tax earnings by an average of approximately $3 million for each of the four 15-month complaint periods. F. Eversource and NSTAR Electric Boston Harbor Civil Action In 2016, the United States Attorney on behalf of the United States Army Corps of Engineers filed a civil action in the United States District Court for the District of Massachusetts against NSTAR Electric, HEEC, and the Massachusetts Water Resources Authority (together with NSTAR Electric and HEEC, the "Defendants"). The action alleged that the Defendants failed to comply with certain permitting requirements related to the placement of the HEEC-owned electric distribution cable beneath Boston Harbor. The parties reached a settlement pursuant to which HEEC agreed to install a new 115kV distribution cable across Boston Harbor to Deer Island, utilizing a different route, and remove portions of the existing cable. Construction of the new distribution cable was completed in August 2019 and removal of the portions of the existing cable was completed in January 2020. On February 9, 2023, the parties filed a Voluntary Stipulation of Dismissal with Prejudice with the United States District Court for the District of Massachusetts whereby the parties agreed to dismiss all remaining claims, crossclaims and counterclaims with prejudice. G. CL&P Regulatory Matters CL&P Tropical Storm Isaias Response Investigation: On April 28, 2021, PURA issued a final decision on CL&P’s compliance with its emergency re

LEASES

LEASES	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
LEASES	LEASES Eversource, including CL&P, NSTAR Electric and PSNH, has entered into lease agreements as a lessee for the use of land, office space, service centers, vehicles, information technology, and equipment. These lease agreements are classified as either finance or operating leases and the liability and right-of-use asset are recognized on the balance sheet at lease commencement. Leases with an initial term of 12 months or less are not recorded on the balance sheet and are recognized as lease expense on a straight-line basis over the lease term. Eversource determines whether or not a contract contains a lease based on whether or not it provides Eversource with the use of a specifically identified asset for a period of time, as well as both the right to direct the use of that asset and receive the significant economic benefits of the asset. Eversource has elected the practical expedient to not separate non-lease components from lease components and instead to account for both as a single lease component, with the exception of the information technology asset class where the lease and non-lease components are separated. The provisions of Eversource, CL&P, NSTAR Electric and PSNH lease agreements contain renewal options. The renewal options range from one year to twenty years. The renewal period is included in the measurement of the lease liability if it is reasonably certain that Eversource will exercise these renewal options. For leases entered into or modified after the January 1, 2019 implementation date of the leases standard under Topic 842, the discount rate utilized for classification and measurement purposes as of the inception date of the lease is based on each company's collateralized incremental interest rate to borrow over a comparable term for an individual lease because the rate implicit in the lease is not determinable. CL&P and PSNH entered into certain contracts for the purchase of energy that qualify as leases. These contracts do not have minimum lease payments and therefore are not recognized as a lease liability on the balance sheet and are not reflected in the future minimum lease payments table below. Expense related to these contracts is included as variable lease cost in the table below. The expense and long-term obligation for these contracts are also included in Note 13B, "Commitments and Contingencies - Long-Term Contractual Arrangements," to the financial statements. The components of lease cost, prior to amounts capitalized, are as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Finance Lease Cost: Amortization of Right-of-use-Assets $ 8.3 $ 4.6 $ 2.6 Interest on Lease Liabilities 2.0 3.9 1.4 Total Finance Lease Cost 10.3 8.5 4.0 Operating Lease Cost 11.6 12.2 11.1 Variable Lease Cost 78.1 61.0 57.8 Total Lease Cost $ 100.0 $ 81.7 $ 72.9 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Finance Lease Cost: Amortization of Right-of-use-Assets $ — $ 0.2 $ 0.1 $ 0.5 $ 0.2 $ 0.1 $ 0.7 $ 0.2 $ 0.1 Interest on Lease Liabilities — 0.6 — 0.1 0.6 — 0.3 0.6 — Total Finance Lease Cost — 0.8 0.1 0.6 0.8 0.1 1.0 0.8 0.1 Operating Lease Cost 0.3 2.3 0.1 0.3 2.3 0.1 0.6 2.1 0.1 Variable Lease Cost 25.6 — 52.5 16.2 — 44.8 12.2 — 45.6 Total Lease Cost $ 25.9 $ 3.1 $ 52.7 $ 17.1 $ 3.1 $ 45.0 $ 13.8 $ 2.9 $ 45.8 Operating lease cost, net of the capitalized portion, is included in Operations and Maintenance (or Purchased Power, Purchased Natural Gas and Transmission expense for transmission leases) on the statements of income. Amortization of finance lease assets is included in Depreciation on the statements of income. Interest expense on finance leases is included in Interest Expense on the statements of income. Supplemental balance sheet information related to leases is as follows: As of December 31, 2022 As of December 31, 2021 (Millions of Dollars) Balance Sheet Classification Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Operating Leases: Right-of-use-Assets, Net Other Long-Term Assets $ 56.9 $ 2.2 $ 22.5 $ — $ 47.2 $ 0.1 $ 24.3 $ 0.3 Operating Lease Liabilities Current Portion Other Current Liabilities $ 9.0 $ 0.6 $ 1.2 $ — $ 10.0 $ 0.1 $ 1.1 $ — Long-Term Other Long-Term Liabilities 47.9 1.6 21.3 — 37.2 — 23.2 0.3 Total Operating Lease Liabilities $ 56.9 $ 2.2 $ 22.5 $ — $ 47.2 $ 0.1 $ 24.3 $ 0.3 Finance Leases: Right-of-use-Assets, Net Property, Plant and Equipment, Net $ 54.5 $ — $ 3.2 $ — $ 58.0 $ — $ 3.3 $ 0.7 Finance Lease Liabilities Current Portion Other Current Liabilities $ 3.8 $ — $ — $ — $ 3.9 $ — $ — $ 0.1 Long-Term Other Long-Term Liabilities 54.2 — 4.9 — 55.4 — 4.9 0.6 Total Finance Lease Liabilities $ 58.0 $ — $ 4.9 $ — $ 59.3 $ — $ 4.9 $ 0.7 The finance lease payments that NSTAR Electric will make over the next twelve months are entirely interest-related, due to escalating payments. As such, none of the finance lease payments over the next twelve months will reduce the finance lease liability. Other information related to leases is as follows: As of December 31, 2022 2021 Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Weighted-Average Remaining Lease Term (Years): Operating Leases 11 4 17 — 13 7 18 7 Finance Leases 15 — 19 — 16 — 20 7 Weighted-Average Discount Rate (Percentage): Operating Leases 3.2 % 3.8 % 4.0 % — % 4.1 % 3.0 % 4.0 % 3.7 % Finance Leases 2.7 % — % 2.9 % — % 2.7 % — % 2.9 % 3.5 % (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2022 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 11.3 $ 0.3 $ 2.1 $ 0.1 Operating Cash Flows from Finance Leases 2.0 — 0.6 — Financing Cash Flows from Finance Leases 3.9 — — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 18.9 2.4 — — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 3.5 — — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2021 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 12.1 $ 0.3 $ 2.1 $ 0.1 Operating Cash Flows from Finance Leases 3.4 0.1 0.6 — Financing Cash Flows from Finance Leases 4.1 1.4 — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 2.1 — 1.9 — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 2.3 — — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2020 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 10.9 $ 0.6 $ 1.8 $ 0.1 Operating Cash Flows from Finance Leases 1.7 0.3 0.6 — Financing Cash Flows from Finance Leases 2.8 1.6 — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 0.6 0.1 0.2 — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 0.7 — 0.3 — In 2020, Eversource also acquired $14.7 million of right-of-use assets in exchange for the assumption of new operating lease liabilities and $54.2 million of right-of-use assets in exchange for the assumption of new finance lease liabilities as a result of the CMA asset acquisition. Future minimum lease payments, excluding variable costs, under long-term leases, as of December 31, 2022 are as follows: Operating Leases Finance Leases (Millions of Dollars) Eversource CL&P NSTAR Electric Eversource NSTAR Electric Year Ending December 31, 2023 $ 10.3 $ 0.7 $ 2.1 $ 5.9 $ 0.6 2024 9.3 0.7 2.1 5.9 0.6 2025 6.4 0.7 1.7 5.9 0.6 2026 5.5 0.3 1.7 5.4 0.7 2027 5.2 — 1.7 5.4 0.7 Thereafter 31.2 — 23.6 50.9 11.8 Future lease payments 67.9 2.4 32.9 79.4 15.0 Less amount representing interest 11.0 0.2 10.4 21.4 10.1 Present value of future minimum lease payments $ 56.9 $ 2.2 $ 22.5 $ 58.0 $ 4.9
LEASES	LEASES Eversource, including CL&P, NSTAR Electric and PSNH, has entered into lease agreements as a lessee for the use of land, office space, service centers, vehicles, information technology, and equipment. These lease agreements are classified as either finance or operating leases and the liability and right-of-use asset are recognized on the balance sheet at lease commencement. Leases with an initial term of 12 months or less are not recorded on the balance sheet and are recognized as lease expense on a straight-line basis over the lease term. Eversource determines whether or not a contract contains a lease based on whether or not it provides Eversource with the use of a specifically identified asset for a period of time, as well as both the right to direct the use of that asset and receive the significant economic benefits of the asset. Eversource has elected the practical expedient to not separate non-lease components from lease components and instead to account for both as a single lease component, with the exception of the information technology asset class where the lease and non-lease components are separated. The provisions of Eversource, CL&P, NSTAR Electric and PSNH lease agreements contain renewal options. The renewal options range from one year to twenty years. The renewal period is included in the measurement of the lease liability if it is reasonably certain that Eversource will exercise these renewal options. For leases entered into or modified after the January 1, 2019 implementation date of the leases standard under Topic 842, the discount rate utilized for classification and measurement purposes as of the inception date of the lease is based on each company's collateralized incremental interest rate to borrow over a comparable term for an individual lease because the rate implicit in the lease is not determinable. CL&P and PSNH entered into certain contracts for the purchase of energy that qualify as leases. These contracts do not have minimum lease payments and therefore are not recognized as a lease liability on the balance sheet and are not reflected in the future minimum lease payments table below. Expense related to these contracts is included as variable lease cost in the table below. The expense and long-term obligation for these contracts are also included in Note 13B, "Commitments and Contingencies - Long-Term Contractual Arrangements," to the financial statements. The components of lease cost, prior to amounts capitalized, are as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Finance Lease Cost: Amortization of Right-of-use-Assets $ 8.3 $ 4.6 $ 2.6 Interest on Lease Liabilities 2.0 3.9 1.4 Total Finance Lease Cost 10.3 8.5 4.0 Operating Lease Cost 11.6 12.2 11.1 Variable Lease Cost 78.1 61.0 57.8 Total Lease Cost $ 100.0 $ 81.7 $ 72.9 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Finance Lease Cost: Amortization of Right-of-use-Assets $ — $ 0.2 $ 0.1 $ 0.5 $ 0.2 $ 0.1 $ 0.7 $ 0.2 $ 0.1 Interest on Lease Liabilities — 0.6 — 0.1 0.6 — 0.3 0.6 — Total Finance Lease Cost — 0.8 0.1 0.6 0.8 0.1 1.0 0.8 0.1 Operating Lease Cost 0.3 2.3 0.1 0.3 2.3 0.1 0.6 2.1 0.1 Variable Lease Cost 25.6 — 52.5 16.2 — 44.8 12.2 — 45.6 Total Lease Cost $ 25.9 $ 3.1 $ 52.7 $ 17.1 $ 3.1 $ 45.0 $ 13.8 $ 2.9 $ 45.8 Operating lease cost, net of the capitalized portion, is included in Operations and Maintenance (or Purchased Power, Purchased Natural Gas and Transmission expense for transmission leases) on the statements of income. Amortization of finance lease assets is included in Depreciation on the statements of income. Interest expense on finance leases is included in Interest Expense on the statements of income. Supplemental balance sheet information related to leases is as follows: As of December 31, 2022 As of December 31, 2021 (Millions of Dollars) Balance Sheet Classification Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Operating Leases: Right-of-use-Assets, Net Other Long-Term Assets $ 56.9 $ 2.2 $ 22.5 $ — $ 47.2 $ 0.1 $ 24.3 $ 0.3 Operating Lease Liabilities Current Portion Other Current Liabilities $ 9.0 $ 0.6 $ 1.2 $ — $ 10.0 $ 0.1 $ 1.1 $ — Long-Term Other Long-Term Liabilities 47.9 1.6 21.3 — 37.2 — 23.2 0.3 Total Operating Lease Liabilities $ 56.9 $ 2.2 $ 22.5 $ — $ 47.2 $ 0.1 $ 24.3 $ 0.3 Finance Leases: Right-of-use-Assets, Net Property, Plant and Equipment, Net $ 54.5 $ — $ 3.2 $ — $ 58.0 $ — $ 3.3 $ 0.7 Finance Lease Liabilities Current Portion Other Current Liabilities $ 3.8 $ — $ — $ — $ 3.9 $ — $ — $ 0.1 Long-Term Other Long-Term Liabilities 54.2 — 4.9 — 55.4 — 4.9 0.6 Total Finance Lease Liabilities $ 58.0 $ — $ 4.9 $ — $ 59.3 $ — $ 4.9 $ 0.7 The finance lease payments that NSTAR Electric will make over the next twelve months are entirely interest-related, due to escalating payments. As such, none of the finance lease payments over the next twelve months will reduce the finance lease liability. Other information related to leases is as follows: As of December 31, 2022 2021 Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Weighted-Average Remaining Lease Term (Years): Operating Leases 11 4 17 — 13 7 18 7 Finance Leases 15 — 19 — 16 — 20 7 Weighted-Average Discount Rate (Percentage): Operating Leases 3.2 % 3.8 % 4.0 % — % 4.1 % 3.0 % 4.0 % 3.7 % Finance Leases 2.7 % — % 2.9 % — % 2.7 % — % 2.9 % 3.5 % (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2022 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 11.3 $ 0.3 $ 2.1 $ 0.1 Operating Cash Flows from Finance Leases 2.0 — 0.6 — Financing Cash Flows from Finance Leases 3.9 — — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 18.9 2.4 — — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 3.5 — — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2021 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 12.1 $ 0.3 $ 2.1 $ 0.1 Operating Cash Flows from Finance Leases 3.4 0.1 0.6 — Financing Cash Flows from Finance Leases 4.1 1.4 — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 2.1 — 1.9 — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 2.3 — — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2020 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 10.9 $ 0.6 $ 1.8 $ 0.1 Operating Cash Flows from Finance Leases 1.7 0.3 0.6 — Financing Cash Flows from Finance Leases 2.8 1.6 — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 0.6 0.1 0.2 — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 0.7 — 0.3 — In 2020, Eversource also acquired $14.7 million of right-of-use assets in exchange for the assumption of new operating lease liabilities and $54.2 million of right-of-use assets in exchange for the assumption of new finance lease liabilities as a result of the CMA asset acquisition. Future minimum lease payments, excluding variable costs, under long-term leases, as of December 31, 2022 are as follows: Operating Leases Finance Leases (Millions of Dollars) Eversource CL&P NSTAR Electric Eversource NSTAR Electric Year Ending December 31, 2023 $ 10.3 $ 0.7 $ 2.1 $ 5.9 $ 0.6 2024 9.3 0.7 2.1 5.9 0.6 2025 6.4 0.7 1.7 5.9 0.6 2026 5.5 0.3 1.7 5.4 0.7 2027 5.2 — 1.7 5.4 0.7 Thereafter 31.2 — 23.6 50.9 11.8 Future lease payments 67.9 2.4 32.9 79.4 15.0 Less amount representing interest 11.0 0.2 10.4 21.4 10.1 Present value of future minimum lease payments $ 56.9 $ 2.2 $ 22.5 $ 58.0 $ 4.9

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS	FAIR VALUE OF FINANCIAL INSTRUMENTS The following methods and assumptions were used to estimate the fair value of each of the following financial instruments: Preferred Stock, Long-Term Debt and Rate Reduction Bonds: The fair value of CL&P's and NSTAR Electric's preferred stock is based upon pricing models that incorporate interest rates and other market factors, valuations or trades of similar securities and cash flow projections. The fair value of long-term debt and RRB debt securities is based upon pricing models that incorporate quoted market prices for those issues or similar issues adjusted for market conditions, credit ratings of the respective companies and treasury benchmark yields. The fair values provided in the table below are classified as Level 2 within the fair value hierarchy. Carrying amounts and estimated fair values are as follows: Eversource CL&P NSTAR Electric PSNH (Millions of Dollars) Carrying Amount Fair Value Carrying Fair Carrying Fair Carrying Fair As of December 31, 2022: Preferred Stock Not Subject to Mandatory Redemption $ 155.6 $ 136.7 $ 116.2 $ 99.2 $ 43.0 $ 37.5 $ — $ — Long-Term Debt 21,044.1 18,891.3 4,216.5 3,828.3 4,425.1 4,091.8 1,164.6 970.5 Rate Reduction Bonds 453.7 424.7 — — — — 453.7 424.7 As of December 31, 2021: Preferred Stock Not Subject to Mandatory Redemption $ 155.6 $ 166.3 $ 116.2 $ 122.3 $ 43.0 $ 44.0 $ — $ — Long-Term Debt 18,216.7 19,636.3 4,215.4 4,848.9 3,985.4 4,453.5 1,163.8 1,220.6 Rate Reduction Bonds 496.9 543.3 — — — — 496.9 543.3 Derivative Instruments and Marketable Securities: Derivative instruments and investments in marketable securities are carried at fair value. For further information, see Note 4, "Derivative Instruments," and Note 5, "Marketable Securities," to the financial statements. See Note 1G, "Summary of Significant Accounting Policies – Fair Value Measurements," for the fair value measurement policy and the fair value hierarchy.

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)	ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) The changes in accumulated other comprehensive income/(loss) by component, net of tax, are as follows: For the Year Ended December 31, 2022 For the Year Ended December 31, 2021 Eversource (Millions of Dollars) Qualified Unrealized Defined Total Qualified Unrealized Defined Total Balance as of January 1st $ (0.4) $ 0.4 $ (42.3) $ (42.3) $ (1.4) $ 1.1 $ (76.1) $ (76.4) OCI Before Reclassifications — (1.6) (2.5) (4.1) — (0.7) 24.1 23.4 Amounts Reclassified from AOCI — — 7.0 7.0 1.0 — 9.7 10.7 Net OCI — (1.6) 4.5 2.9 1.0 (0.7) 33.8 34.1 Balance as of December 31st $ (0.4) $ (1.2) $ (37.8) $ (39.4) $ (0.4) $ 0.4 $ (42.3) $ (42.3) Defined benefit plan OCI amounts before reclassifications relate to actuarial gains and losses that arose during the year and were recognized in AOCI. The unamortized actuarial gains and losses and prior service costs on the defined benefit plans are amortized from AOCI into Other Income, Net over the average future employee service period, and are reflected in amounts reclassified from AOCI. The related tax effects of the defined benefit plan OCI amounts before reclassifications recognized in AOCI were net deferred tax assets of $1.3 million and $6.0 million in 2022 and 2020, respectively and were net deferred tax liabilities of $8.3 million in 2021. The following table sets forth the amounts reclassified from AOCI by component and the impacted line item on the statements of income: Amounts Reclassified from AOCI Eversource (Millions of Dollars) For the Years Ended December 31, Statements of Income 2022 2021 2020 Qualified Cash Flow Hedging Instruments $ — $ (1.7) $ (2.5) Interest Expense Tax Effect — 0.7 0.9 Income Tax Expense Qualified Cash Flow Hedging Instruments, Net of Tax $ — $ (1.0) $ (1.6) Defined Benefit Plan Costs: Amortization of Actuarial Losses $ (9.0) $ (13.1) $ (8.1) Other Income, Net (1) Amortization of Prior Service Cost (0.3) — (0.3) Other Income, Net (1) Total Defined Benefit Plan Costs (9.3) (13.1) (8.4) Tax Effect 2.3 3.4 2.1 Income Tax Expense Defined Benefit Plan Costs, Net of Tax $ (7.0) $ (9.7) $ (6.3) Total Amounts Reclassified from AOCI, Net of Tax $ (7.0) $ (10.7) $ (7.9) (1) These amounts are included in the computation of net periodic Pension, SERP and PBOP costs. See Note 1K, "Summary of Significant Accounting Policies – Other Income, Net" and Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," for further information.

DIVIDEND RESTRICTIONS

DIVIDEND RESTRICTIONS	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
DIVIDEND RESTRICTIONS	DIVIDEND RESTRICTIONS Eversource parent's ability to pay dividends may be affected by certain state statutes, the ability of its subsidiaries to pay common dividends and the leverage restriction tied to its consolidated total indebtedness to total capitalization ratio requirement in its revolving credit agreements. Pursuant to the joint revolving credit agreement of Eversource, CL&P, PSNH, NSTAR Gas, Yankee Gas, EGMA and Aquarion Water Company of Connecticut, and to the NSTAR Electric revolving credit agreement, each company is required to maintain consolidated total indebtedness to total capitalization ratio of no greater than 65 percent at the end of each fiscal quarter. As of December 31, 2022, all companies were in compliance with such covenant and in compliance with all such provisions of the revolving credit agreements that may restrict the payment of dividends as of December 31, 2022. The Retained Earnings balances subject to dividend restrictions were $5.53 billion for Eversource, $2.46 billion for CL&P, $2.92 billion for NSTAR Electric and $572.1 million for PSNH as of December 31, 2022.

COMMON SHARES

COMMON SHARES	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
COMMON SHARES	COMMON SHARES The following table sets forth the Eversource parent common shares and the shares of common stock of CL&P, NSTAR Electric and PSNH that were authorized and issued, as well as the respective per share par values: Shares Par Value Authorized as of December 31, 2022 and 2021 Issued as of December 31, 2022 2021 Eversource $ 5 380,000,000 359,984,073 357,818,402 CL&P $ 10 24,500,000 6,035,205 6,035,205 NSTAR Electric $ 1 100,000,000 200 200 PSNH $ 1 100,000,000 301 301 Common Share Issuances and 2022 Equity Distribution Agreement: On May 11, 2022, Eversource entered into an equity distribution agreement pursuant to which it may offer and sell up to $1.2 billion of its common shares from time to time through an “at-the-market” (ATM) equity offering program. Eversource may issue and sell its common shares through its sales agents during the term of this agreement. Shares may be offered in transactions on the New York Stock Exchange, in the over-the-counter market, through negotiated transactions or otherwise. Sales may be made at either market prices prevailing at the time of sale, at prices related to such prevailing market prices or at negotiated prices. In 2022, Eversource issued 2,165,671 common shares, which resulted in proceeds of $197.1 million, net of issuance costs. Eversource used the net proceeds received for general corporate purposes. Treasury Shares: As of December 31, 2022 and 2021, there were 11,540,218 and 13,415,206 Eversource common shares held as treasury shares, respectively. As of December 31, 2022 and 2021, there were 348,443,855 and 344,403,196 Eversource common shares outstanding, respectively. Acquisition of The Torrington Water Company: On October 3, 2022, Aquarion acquired The Torrington Water Company (TWC) following the receipt of all required approvals. The acquisition was structured as a stock-for-stock exchange, and Eversource issued 925,264 treasury shares at closing for a purchase price of $72.1 million. Acquisition of New England Service Company: On December 1, 2021, Aquarion acquired New England Service Company (NESC), pursuant to a definitive agreement entered into on April 8, 2021. The acquisition was structured as a stock-for-stock merger and Eversource issued 462,517 treasury shares at closing for a purchase price of $38.1 million. Eversource issues treasury shares to satisfy awards under the Company's incentive plans, shares issued under the dividend reinvestment and share purchase plan, and matching contributions under the Eversource 401k Plan. Eversource also issued treasury shares for its December 2021 and October 2022 water business acquisitions. The issuance of treasury shares represents a non-cash transaction, as the treasury shares were used to fulfill Eversource's obligations that require the issuance of common shares.

PREFERRED STOCK NOT SUBJECT TO

PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION	PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTIONThe CL&P and NSTAR Electric preferred stock is not subject to mandatory redemption and is presented as a noncontrolling interest of a subsidiary in Eversource's financial statements. Details of preferred stock not subject to mandatory redemption are as follows (in millions, except in redemption price and shares): Redemption Price Shares Outstanding as of December 31, As of December 31, Series 2022 2021 2022 2021 CL&P $1.90 Series of 1947 $ 52.50 163,912 163,912 $ 8.2 $ 8.2 $2.00 Series of 1947 $ 54.00 336,088 336,088 16.8 16.8 $2.04 Series of 1949 $ 52.00 100,000 100,000 5.0 5.0 $2.20 Series of 1949 $ 52.50 200,000 200,000 10.0 10.0 3.90% Series of 1949 $ 50.50 160,000 160,000 8.0 8.0 $2.06 Series E of 1954 $ 51.00 200,000 200,000 10.0 10.0 $2.09 Series F of 1955 $ 51.00 100,000 100,000 5.0 5.0 4.50% Series of 1956 $ 50.75 104,000 104,000 5.2 5.2 4.96% Series of 1958 $ 50.50 100,000 100,000 5.0 5.0 4.50% Series of 1963 $ 50.50 160,000 160,000 8.0 8.0 5.28% Series of 1967 $ 51.43 200,000 200,000 10.0 10.0 $3.24 Series G of 1968 $ 51.84 300,000 300,000 15.0 15.0 6.56% Series of 1968 $ 51.44 200,000 200,000 10.0 10.0 Total CL&P 2,324,000 2,324,000 $ 116.2 $ 116.2 NSTAR Electric 4.25% Series of 1956 $ 103.625 180,000 180,000 $ 18.0 $ 18.0 4.78% Series of 1958 $ 102.80 250,000 250,000 25.0 25.0 Total NSTAR Electric 430,000 430,000 $ 43.0 $ 43.0 Fair Value Adjustment due to Merger with NSTAR (3.6) (3.6) Other 6.00% Series of 1958 $ 100.00 23 23 $ — $ — Total Eversource - Noncontrolling Interest - Preferred Stock of Subsidiaries $ 155.6 $ 155.6

COMMON SHAREHOLDERS' EQUITY AND

COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS	COMMON SHARES The following table sets forth the Eversource parent common shares and the shares of common stock of CL&P, NSTAR Electric and PSNH that were authorized and issued, as well as the respective per share par values: Shares Par Value Authorized as of December 31, 2022 and 2021 Issued as of December 31, 2022 2021 Eversource $ 5 380,000,000 359,984,073 357,818,402 CL&P $ 10 24,500,000 6,035,205 6,035,205 NSTAR Electric $ 1 100,000,000 200 200 PSNH $ 1 100,000,000 301 301 Common Share Issuances and 2022 Equity Distribution Agreement: On May 11, 2022, Eversource entered into an equity distribution agreement pursuant to which it may offer and sell up to $1.2 billion of its common shares from time to time through an “at-the-market” (ATM) equity offering program. Eversource may issue and sell its common shares through its sales agents during the term of this agreement. Shares may be offered in transactions on the New York Stock Exchange, in the over-the-counter market, through negotiated transactions or otherwise. Sales may be made at either market prices prevailing at the time of sale, at prices related to such prevailing market prices or at negotiated prices. In 2022, Eversource issued 2,165,671 common shares, which resulted in proceeds of $197.1 million, net of issuance costs. Eversource used the net proceeds received for general corporate purposes. Treasury Shares: As of December 31, 2022 and 2021, there were 11,540,218 and 13,415,206 Eversource common shares held as treasury shares, respectively. As of December 31, 2022 and 2021, there were 348,443,855 and 344,403,196 Eversource common shares outstanding, respectively. Acquisition of The Torrington Water Company: On October 3, 2022, Aquarion acquired The Torrington Water Company (TWC) following the receipt of all required approvals. The acquisition was structured as a stock-for-stock exchange, and Eversource issued 925,264 treasury shares at closing for a purchase price of $72.1 million. Acquisition of New England Service Company: On December 1, 2021, Aquarion acquired New England Service Company (NESC), pursuant to a definitive agreement entered into on April 8, 2021. The acquisition was structured as a stock-for-stock merger and Eversource issued 462,517 treasury shares at closing for a purchase price of $38.1 million. Eversource issues treasury shares to satisfy awards under the Company's incentive plans, shares issued under the dividend reinvestment and share purchase plan, and matching contributions under the Eversource 401k Plan. Eversource also issued treasury shares for its December 2021 and October 2022 water business acquisitions. The issuance of treasury shares represents a non-cash transaction, as the treasury shares were used to fulfill Eversource's obligations that require the issuance of common shares.

REVENUES

REVENUES	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
REVENUES	REVENUES Revenue is recognized when promised goods or services (referred to as performance obligations) are transferred to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. A five-step model is used for recognizing and measuring revenue from contracts with customers, which includes identifying the contract with the customer, identifying the performance obligations promised within the contract, determining the transaction price (the amount of consideration to which the company expects to be entitled), allocating the transaction price to the performance obligations and recognizing revenue when (or as) the performance obligation is satisfied. The following tables present operating revenues disaggregated by revenue source: For the Year Ended December 31, 2022 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 4,796.1 $ 1,204.9 $ — $ 141.7 $ — $ — $ 6,142.7 Commercial 2,903.3 648.5 — 66.5 — (4.1) 3,614.2 Industrial 374.9 199.7 — 4.7 — (20.1) 559.2 Total Retail Tariff Sales Revenues 8,074.3 2,053.1 — 212.9 — (24.2) 10,316.1 Wholesale Transmission Revenues — — 1,700.5 — — (1,264.5) 436.0 Wholesale Market Sales Revenues 1,190.9 140.8 — 3.8 — — 1,335.5 Other Revenues from Contracts with Customers 72.3 5.6 14.1 8.4 1,435.5 (1,425.3) 110.6 Amortization of/(Reserve for) Revenues 72.0 — 0.7 (0.7) — — 72.0 Total Revenues from Contracts with Customers 9,409.5 2,199.5 1,715.3 224.4 1,435.5 (2,714.0) 12,270.2 Alternative Revenue Programs (15.4) 14.8 92.7 (2.5) — (84.3) 5.3 Other Revenues 11.2 1.3 0.7 0.6 — — 13.8 Total Operating Revenues $ 9,405.3 $ 2,215.6 $ 1,808.7 $ 222.5 $ 1,435.5 $ (2,798.3) $ 12,289.3 For the Year Ended December 31, 2021 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 3,989.8 $ 1,000.3 $ — $ 133.5 $ — $ — $ 5,123.6 Commercial 2,486.1 497.6 — 62.8 — (5.1) 3,041.4 Industrial 345.3 167.2 — 4.3 — (17.1) 499.7 Total Retail Tariff Sales Revenues 6,821.2 1,665.1 — 200.6 — (22.2) 8,664.7 Wholesale Transmission Revenues — — 1,751.3 — 86.6 (1,384.7) 453.2 Wholesale Market Sales Revenues 575.8 82.1 — 3.9 — — 661.8 Other Revenues from Contracts with Customers 78.1 5.1 13.6 7.5 1,267.4 (1,257.7) 114.0 Reserve for Revenues Subject to Refund (71.1) — (5.0) (2.6) — — (78.7) Total Revenues from Contracts with Customers 7,404.0 1,752.3 1,759.9 209.4 1,354.0 (2,664.6) 9,815.0 Alternative Revenue Programs 14.7 37.0 (126.1) 1.5 — 114.6 41.7 Other Revenues 4.9 0.3 0.8 0.4 — — 6.4 Total Operating Revenues $ 7,423.6 $ 1,789.6 $ 1,634.6 $ 211.3 $ 1,354.0 $ (2,550.0) $ 9,863.1 For the Year Ended December 31, 2020 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 3,951.5 $ 644.9 $ — $ 145.1 $ — $ — $ 4,741.5 Commercial 2,353.4 361.9 — 62.4 — (4.8) 2,772.9 Industrial 327.1 107.4 — 4.8 — (13.7) 425.6 Total Retail Tariff Sales Revenues 6,632.0 1,114.2 — 212.3 — (18.5) 7,940.0 Wholesale Transmission Revenues — — 1,557.3 — 74.2 (1,290.6) 340.9 Wholesale Market Sales Revenues 327.3 43.0 — 3.8 — — 374.1 Other Revenues from Contracts with Customers 79.3 5.7 13.3 3.5 1,161.7 (1,152.0) 111.5 Total Revenues from Contracts with Customers 7,038.6 1,162.9 1,570.6 219.6 1,235.9 (2,461.1) 8,766.5 Alternative Revenue Programs 88.1 44.7 (35.2) (4.7) — 37.1 130.0 Other Revenues 5.6 1.1 0.7 0.5 — — 7.9 Total Operating Revenues $ 7,132.3 $ 1,208.7 $ 1,536.1 $ 215.4 $ 1,235.9 $ (2,424.0) $ 8,904.4 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH Revenues from Contracts with Customers Retail Tariff Sales Residential $ 2,397.2 $ 1,601.8 $ 797.1 $ 1,994.2 $ 1,375.8 $ 619.8 $ 2,011.1 $ 1,365.8 $ 574.6 Commercial 1,067.9 1,457.4 380.8 890.6 1,265.0 332.2 878.3 1,176.8 299.9 Industrial 146.4 135.8 92.7 131.4 119.1 94.8 137.5 106.4 83.2 Total Retail Tariff Sales Revenues 3,611.5 3,195.0 1,270.6 3,016.2 2,759.9 1,046.8 3,026.9 2,649.0 957.7 Wholesale Transmission Revenues 755.1 670.4 275.0 863.3 616.3 271.7 754.8 576.5 226.0 Wholesale Market Sales Revenues 873.7 215.0 102.2 408.8 109.2 57.8 230.1 58.4 38.8 Other Revenues from Contracts 30.2 46.9 11.8 26.7 56.2 11.3 32.9 43.6 14.2 Amortization of/(Reserve for) Revenues 72.7 — — (76.1) — — — — 4.6 Total Revenues from Contracts 5,343.2 4,127.3 1,659.6 4,238.9 3,541.6 1,387.6 4,044.7 3,327.5 1,241.3 Alternative Revenue Programs 56.5 0.7 20.1 (78.9) (15.1) (17.4) (4.2) 54.5 2.6 Other Revenues 1.8 7.2 2.9 0.4 3.4 1.9 2.2 3.5 0.6 Eliminations (583.8) (552.1) (207.8) (523.0) (473.5) (194.9) (495.2) (444.4) (165.4) Total Operating Revenues $ 4,817.7 $ 3,583.1 $ 1,474.8 $ 3,637.4 $ 3,056.4 $ 1,177.2 $ 3,547.5 $ 2,941.1 $ 1,079.1 Retail Tariff Sales: Regulated utilities provide products and services to their regulated customers under rates, pricing, payment terms and conditions of service, regulated by each state regulatory agency. The arrangement whereby a utility provides commodity service to a customer for a price approved by the respective state regulatory commission is referred to as a tariff sale contract, and the tariff governs all aspects of the provision of regulated services by utilities. The majority of revenue for Eversource, CL&P, NSTAR Electric and PSNH is derived from regulated retail tariff sales for the sale and distribution of electricity, natural gas and water to residential, commercial and industrial retail customers. The utility's performance obligation for the regulated tariff sales is to provide electricity, natural gas or water to the customer as demanded. The promise to provide the commodity represents a single performance obligation, as it is a promise to transfer a series of distinct goods or services that are substantially the same and that have the same pattern of transfer to the customer. Revenue is recognized over time as the customer simultaneously receives and consumes the benefits provided by the utility, and the utility satisfies its performance obligation. Revenue is recognized based on the output method as there is a directly observable output to the customer (electricity, natural gas or water units delivered to the customer and immediately consumed). Each Eversource utility is entitled to be compensated for performance completed to date (service taken by the customer) until service is terminated. In regulated tariff sales, the transaction prices are the rates approved by the respective state regulatory commissions. In general, rates can only be changed through formal proceedings with the state regulatory commissions. These rates are designed to recover the costs to provide service to customers and include a return on investment. Regulatory commission-approved tracking mechanisms are included in these rates and are also used to recover, on a fully-reconciling basis, certain costs, such as the procurement of energy supply, retail transmission charges, energy efficiency program costs, net metering for distributed generation, and restructuring and stranded costs, among others. These tracking mechanisms result in rates being changed periodically to ensure recovery of actual costs incurred and the refund of any overcollection of costs. Customers may elect to purchase electricity from each Eversource electric utility or may contract separately with a competitive third party supplier. Revenue is not recorded for the sale of the electricity commodity to customers who have contracted separately with these suppliers, only the delivery to a customer, as the utility is acting as an agent on behalf of the third party supplier. Wholesale Transmission Revenues: The Eversource electric transmission-owning companies (CL&P, NSTAR Electric and PSNH) each own and maintain transmission facilities that are part of an interstate power transmission grid over which electricity is transmitted throughout New England. CL&P, NSTAR Electric and PSNH, as well as most other New England utilities, are parties to a series of agreements that provide for coordinated planning and operation of the region's transmission facilities and the rules by which they acquire transmission services. The Eversource electric transmission-owning companies have a combination of FERC-approved regional and local formula rates that work in tandem to recover all their transmission costs. These rates are part of the ISO-NE Tariff. Regional rates recover the costs of higher voltage transmission facilities that benefit the region and are collected from all New England transmission customers, including the Eversource distribution businesses. Eversource's local rates recover the costs of transmission facilities that do not provide a benefit to the region, and are collected from Eversource's distribution businesses and other transmission customers. The distribution businesses of Eversource, in turn, recover the FERC approved charges from retail customers through annual tracking mechanisms, which are retail tariff sales. The utility's performance obligation for regulated wholesale transmission sales is to provide transmission services to the customer as demanded. The promise to provide transmission service represents a single performance obligation. The transaction prices are the transmission rate formulas as defined by the ISO-NE Tariff and are regulated and established by FERC. Wholesale transmission revenue is recognized over time as the performance obligation is completed, which occurs as transmission services are provided to customers. The revenue is recognized based on the output method. Each Eversource utility is entitled to be compensated for performance completed to date (e.g., use of the transmission system by the customer). Wholesale Market Sales Revenues: Wholesale market sales transactions include sales of energy and energy-related products into the ISO-NE wholesale electricity market, sales of natural gas to third party marketers, and also the sale of RECs to various counterparties. ISO-NE oversees the region's wholesale electricity market and administers the transactions and terms and conditions, including payment terms, which are established in the ISO-NE tariff, between the buyers and sellers in the market. Pricing is set by the wholesale market. The wholesale transactions in the ISO-NE market occur on a day-ahead basis or a real-time basis (daily) and are, therefore, short-term. Transactions are tracked and reported by ISO-NE net by the hour, which is the net hourly position of energy sales and purchases by each market participant. The performance obligation for ISO-NE energy transactions is defined to be the net by hour transaction. Revenue is recognized when the performance obligation for these energy sales transactions is satisfied, which is when the sale occurs and the energy is transferred to the customer. For sales of natural gas, transportation, and natural gas pipeline capacity to third party marketers, revenue is recognized when the performance obligation is satisfied at the point in time the sale occurs and the natural gas or related product is transferred to the marketer. RECs are sold to various counterparties, and revenue is recognized when the performance obligation is satisfied upon transfer of title to the customer through the New England Power Pool Generation Information System. Wholesale transactions also include the sale of CL&P’s, NSTAR Electric’s and PSNH’s transmission rights associated with their proportionate equity ownership share in the transmission lines of the Hydro-Québec system in Canada. Other Revenues from Contracts with Customers: Other revenues from contracts with customers primarily include property rentals that are not deemed leases. These revenues are generally recognized on a straight-line basis over time as the service is provided to the customer. Other revenues also include revenues from Eversource's service company, which is eliminated in consolidation. Amortization of/(Reserve for) Revenues Subject to Refund: A reserve is recorded as a reduction to revenues when future refunds to customers are deemed probable. The reserve is reversed as refunds are provided to customers in rates. Amortization of Revenues Subject to Refund within the Electric Distribution segment in 2022 represents the reversal of a 2021 reserve at CL&P established to provide bill credits to customers as a result of the settlement agreement on October 1, 2021 and a storm performance penalty assessed by PURA. The reserve was reversed as customer credits were distributed to CL&P’s customers in retail electric rates. Total customer credits as a result of the 2021 settlement and civil penalty of $93.4 million were recorded as a reserve for revenues subject to refund within current regulatory liabilities and reflected as a reduction to Operating Revenues on the 2021 income statement. The settlement amount of $65 million was refunded over a two-month billing period from December 1, 2021 to January 31, 2022 and the civil penalty of $28.4 million was refunded over a one year billing period, which began September 1, 2021. The Connecticut water business continues to record a regulatory liability and reduction to revenues to reflect the difference between the 35 percent federal corporate income tax rate included in base distribution rates charged to customers and the 21 percent federal corporate income tax rate currently effective. This reserve will continue until base distribution rates are updated to reflect the lower federal tax rate. Alternative Revenue Programs: In accordance with accounting guidance for rate-regulated operations, certain of Eversource's utilities' rate making mechanisms qualify as alternative revenue programs (ARPs) if they meet specified criteria, in which case revenues may be recognized prior to billing based on allowed levels of collection in rates. Eversource's utility companies recognize revenue and record a regulatory asset or liability once the condition or event allowing for the automatic adjustment of future rates occurs. ARP revenues include both the recognition of the deferral adjustment to ARP revenues, when the regulator-specified condition or event allowing for additional billing or refund has occurred, and an equal and offsetting reversal of the ARP deferral to revenues as those amounts are reflected in the price of service in subsequent periods. Eversource’s ARPs include the revenue decoupling mechanism, the annual reconciliation adjustment to transmission formula rates, and certain capital tracker mechanisms. Certain Eversource electric, natural gas and water companies, including CL&P and NSTAR Electric, have revenue decoupling mechanisms approved by a regulatory commission (decoupled companies). Decoupled companies’ distribution revenues are not directly based on sales volumes. The decoupled companies reconcile their annual base distribution rate recovery to pre-established levels of baseline distribution delivery service revenues, with any difference between the allowed level of distribution revenue and the actual amount realized adjusted through subsequent rates. The transmission formula rates provide for the annual reconciliation and recovery or refund of estimated costs to actual costs. The financial impacts of differences between actual and estimated costs are deferred for future recovery from, or refund to, transmission customers. This transmission deferral reconciles billed transmission revenues to the revenue requirement for our transmission businesses. Other Revenues: Other Revenues include certain fees charged to customers that are not considered revenue from contracts with customers. Other revenues Intercompany Eliminations: Intercompany eliminations are primarily related to the Eversource electric transmission revenues that are derived from ISO-NE regional transmission charges to the distribution businesses of CL&P, NSTAR Electric and PSNH that recover the costs of the wholesale transmission business, and revenues from Eversource's service company. Intercompany revenues and expenses between the Eversource wholesale transmission businesses and the Eversource distribution businesses and from Eversource's service company are eliminated in consolidation and included in "Eliminations" in the tables above. Receivables: Receivables, Net on the balance sheet primarily includes trade receivables from retail customers and customers related to wholesale transmission contracts, wholesale market sales, sales of RECs, and property rentals. In general, retail tariff customers and wholesale transmission customers are billed monthly and the payment terms are generally due and payable upon receipt of the bill. Unbilled Revenues: Unbilled Revenues on the balance sheet represent estimated amounts due from retail customers for electricity, natural gas or water delivered to customers but not yet billed. The utility company has satisfied its performance obligation and the customer has received and consumed the commodity as of the balance sheet date, and therefore, the utility company records revenue for those services in the period the services were provided. Only the passage of time is required before the company is entitled to payment for the satisfaction of the performance obligation. Payment from customers is due monthly as services are rendered and amounts are billed. Actual amounts billed to customers when meter readings become available may vary from the estimated amount. Unbilled revenues are recognized by allocating estimated unbilled sales volumes to the respective customer classes, and then applying an estimated rate by customer class to those sales volumes. Unbilled revenue estimates reflect seasonality, weather, customer usage patterns, customer rates in effect for customer classes, and the timing of customer billing. The companies that have a decoupling mechanism record a regulatory deferral to reflect the actual allowed amount of revenue associated with their respective decoupled distribution rate design.

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE Basic EPS is computed based upon the weighted average number of common shares outstanding during each period. Diluted EPS is computed on the basis of the weighted average number of common shares outstanding plus the potential dilutive effect of certain share-based compensation awards and the equity forward sale agreement, as if they were converted into outstanding common shares. The dilutive effect of unvested RSU and performance share awards, as well as the equity forward sale agreement, is calculated using the treasury stock method. RSU and performance share awards are included in basic weighted average common shares outstanding as of the date that all necessary vesting conditions have been satisfied. Earnings per share dilution related to the equity forward sale agreement was determined under the treasury stock method until settlement of the forward sale agreement. Under this method, the number of Eversource common shares used in calculating diluted EPS was deemed to be increased by the excess, if any, of the number of shares that would be issued upon physical settlement of the forward sale agreement less the number of shares that would be purchased by Eversource in the market (based on the average market price during the same reporting period) using the proceeds receivable upon settlement (based on the adjusted forward sale price at the end of that reporting period). Share dilution occurred when the average market price of Eversource's common shares was higher than the adjusted forward sale price. Eversource physically settled all remaining shares under the forward sale agreement as of March 26, 2020. For the years ended December 31, 2022 and 2021, there were no antidilutive share awards excluded from the computation. For the year ended December 31, 2020, 39,560 antidilutive share awards were excluded from the EPS computation, as their impact would have been antidilutive . Antidilutive shares pertained to a purchase option extended to underwriters in connection with Eversource's June 2020 common share issuance. The following table sets forth the components of basic and diluted EPS: Eversource (Millions of Dollars, except share information) For the Years Ended December 31, 2022 2021 2020 Net Income Attributable to Common Shareholders $ 1,404.9 $ 1,220.5 $ 1,205.2 Weighted Average Common Shares Outstanding: Basic 346,783,444 343,972,926 338,836,147 Dilutive Effect of: Share-Based Compensation Awards and Other 463,324 658,130 738,994 Equity Forward Sale Agreement — — 271,921 Total Dilutive Effect 463,324 658,130 1,010,915 Diluted 347,246,768 344,631,056 339,847,062 Basic EPS $ 4.05 $ 3.55 $ 3.56 Diluted EPS $ 4.05 $ 3.54 $ 3.55

SEGMENT INFORMATION

SEGMENT INFORMATION	12 Months Ended
	Dec. 31, 2022
Segment Reporting [Abstract]
SEGMENT INFORMATION	SEGMENT INFORMATION Eversource is organized into the Electric Distribution, Electric Transmission, Natural Gas Distribution and Water Distribution reportable segments and Other based on a combination of factors, including the characteristics of each segments' services, the sources of operating revenues and expenses and the regulatory environment in which each segment operates. These reportable segments represent substantially all of Eversource's total consolidated revenues. Revenues from the sale of electricity, natural gas and water primarily are derived from residential, commercial and industrial customers and are not dependent on any single customer. The Electric Distribution reportable segment includes the results of NSTAR Electric's solar power facilities. Eversource's reportable segments are determined based upon the level at which Eversource's chief operating decision maker assesses performance and makes decisions about the allocation of company resources. The remainder of Eversource's operations is presented as Other in the tables below and primarily consists of 1) the equity in earnings of Eversource parent from its subsidiaries and intercompany interest income, both of which are eliminated in consolidation, and interest expense related to the debt of Eversource parent, 2) the revenues and expenses of Eversource Service, most of which are eliminated in consolidation, 3) the operations of CYAPC and YAEC, 4) the results of other unregulated subsidiaries, which are not part of its core business, and 5) Eversource parent's equity ownership interests that are not consolidated, which primarily include the offshore wind business, a natural gas pipeline owned by Enbridge, Inc., and a renewable energy investment fund. In the ordinary course of business, Yankee Gas, NSTAR Gas and EGMA purchase natural gas transmission services from the Enbridge, Inc. natural gas pipeline project described above. These affiliate transaction costs total $77.7 million annually and are classified as Purchased Power, Purchased Natural Gas and Transmission on the Eversource statements of income. Each of Eversource's subsidiaries, including CL&P, NSTAR Electric and PSNH, has one reportable segment. Cash flows used for investments in plant included in the segment information below are cash capital expenditures that do not include amounts incurred on capital projects but not yet paid, cost of removal, AFUDC related to equity funds, and the capitalized and deferred portions of pension and PBOP income/expense. Eversource's segment information is as follows: For the Year Ended December 31, 2022 Eversource (Millions of Dollars) Electric Natural Gas Electric Transmission Water Distribution Other Eliminations Total Operating Revenues $ 9,405.3 $ 2,215.6 $ 1,808.7 $ 222.5 $ 1,435.5 $ (2,798.3) $ 12,289.3 Depreciation and Amortization (970.4) (157.6) (337.4) (50.9) (132.6) 5.8 (1,643.1) Other Operating Expenses (7,663.7) (1,727.0) (548.4) (111.8) (1,189.1) 2,792.0 (8,448.0) Operating Income 771.2 331.0 922.9 59.8 113.8 (0.5) 2,198.2 Interest Expense (253.1) (71.4) (145.5) (34.7) (247.8) 74.2 (678.3) Interest Income 45.1 10.2 0.5 — 66.3 (71.6) 50.5 Other Income, Net 180.4 33.6 37.9 8.5 1,600.8 (1,565.6) 295.6 Income Tax (Expense)/Benefit (146.2) (69.2) (216.3) 3.2 (25.1) — (453.6) Net Income 597.4 234.2 599.5 36.8 1,508.0 (1,563.5) 1,412.4 Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income Attributable to Common Shareholders $ 592.8 $ 234.2 $ 596.6 $ 36.8 $ 1,508.0 $ (1,563.5) $ 1,404.9 Total Assets (as of) $ 27,365.0 $ 8,084.9 $ 13,369.5 $ 2,783.8 $ 26,365.2 $ (24,737.5) $ 53,230.9 Cash Flows Used for Investments in Plant $ 1,172.6 $ 710.3 $ 1,144.0 $ 154.4 $ 260.6 $ — $ 3,441.9 For the Year Ended December 31, 2021 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Operating Revenues $ 7,423.6 $ 1,789.6 $ 1,634.6 $ 211.3 $ 1,354.0 $ (2,550.0) $ 9,863.1 Depreciation and Amortization (737.8) (142.3) (300.3) (46.1) (113.1) 4.6 (1,335.0) Other Operating Expenses (5,970.0) (1,345.4) (496.2) (101.4) (1,170.4) 2,548.6 (6,534.8) Operating Income 715.8 301.9 838.1 63.8 70.5 3.2 1,993.3 Interest Expense (236.4) (58.6) (133.2) (32.0) (168.8) 46.6 (582.4) Interest Income 20.7 4.5 2.2 — 46.0 (47.8) 25.6 Other Income, Net 78.1 17.9 19.8 3.3 1,363.9 (1,347.3) 135.7 Income Tax (Expense)/Benefit (103.5) (60.9) (179.4) 1.7 (2.1) — (344.2) Net Income 474.7 204.8 547.5 36.8 1,309.5 (1,345.3) 1,228.0 Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income Attributable to Common Shareholders $ 470.1 $ 204.8 $ 544.6 $ 36.8 $ 1,309.5 $ (1,345.3) $ 1,220.5 Total Assets (as of) $ 25,411.2 $ 7,215.9 $ 12,377.8 $ 2,551.1 $ 22,674.7 $ (21,738.6) $ 48,492.1 Cash Flows Used for Investments in Plant $ 1,053.3 $ 721.1 $ 1,024.1 $ 137.2 $ 239.4 $ — $ 3,175.1 For the Year Ended December 31, 2020 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Operating Revenues $ 7,132.3 $ 1,208.7 $ 1,536.1 $ 215.4 $ 1,235.9 $ (2,424.0) $ 8,904.4 Depreciation and Amortization (657.0) (87.9) (278.1) (44.2) (93.5) 1.6 (1,159.1) Other Operating Expenses (5,642.3) (913.8) (470.0) (86.6) (1,071.9) 2,428.0 (5,756.6) Operating Income 833.0 207.0 788.0 84.6 70.5 5.6 1,988.7 Interest Expense (216.0) (40.0) (126.8) (32.9) (161.0) 38.3 (538.4) Interest Income 3.2 0.9 4.7 — 37.8 (41.8) 4.8 Other Income, Net 58.0 3.1 23.3 2.0 1,382.9 (1,365.5) 103.8 Income Tax (Expense)/Benefit (129.6) (36.9) (183.8) (12.5) 16.6 — (346.2) Net Income 548.6 134.1 505.4 41.2 1,346.8 (1,363.4) 1,212.7 Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income Attributable to Common Shareholders $ 544.0 $ 134.1 $ 502.5 $ 41.2 $ 1,346.8 $ (1,363.4) $ 1,205.2 Cash Flows Used for Investments in Plant $ 1,079.0 $ 494.4 $ 1,004.6 $ 118.8 $ 246.2 $ — $ 2,943.0

ACQUISITION OF ASSETS OF COLUMB

ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS	12 Months Ended
	Dec. 31, 2022
Business Combination and Asset Acquisition [Abstract]
ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS	ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS On October 9, 2020, Eversource acquired certain assets and liabilities that comprised the NiSource Inc. (NiSource) natural gas distribution business in Massachusetts, which was previously doing business as Columbia Gas of Massachusetts (CMA), pursuant to an asset purchase agreement (the Agreement) entered into on February 26, 2020 between Eversource and NiSource. The cash purchase price was $1.1 billion, plus a working capital amount of $68.6 million, as finalized in 2021. Eversource financed the acquisition through a combination of debt and equity issuances in a ratio that was consistent with its consolidated capital structure. Pro Forma Financial Information: The following unaudited pro forma financial information reflects the pro forma combined results of operations of Eversource and the CMA business acquired and reflects the amortization of purchase price adjustments assuming the acquisition had taken place on January 1, 2019. The unaudited pro forma financial information has been presented for illustrative purposes only and is not necessarily indicative of the consolidated results of operations that would have been achieved or the future consolidated results of operations of Eversource. Pro forma net income excludes the impact of assets and liabilities not assumed by Eversource and non-recurring costs associated with the transaction. (Pro forma amounts in millions, except share amounts) For the Year Ended Operating Revenues $ 9,273 Net Income Attributable to Common Shareholders 1,265 Basic EPS 3.73 Diluted EPS 3.72 Revenues and Net Income: The impact of CMA on Eversource's accompanying consolidated statement of income included operating revenues of $154.8 million and net income attributable to common shareholders of $13.9 million for the year ended December 31, 2020. Transactions recognized separately from the business combination: Eversource entered into Transition Services Agreements (TSAs) with NiSource, under which NiSource provided certain administrative functions. The TSAs were completed in 2022. Eversource recorded $7.9 million and $21.4 million in Operating Expenses on the statements of income related to TSA costs for the years ended December 31, 2022 and 2021, respectively, and $15.9 million of TSA and pre-TSA costs in Operating Expenses in 2020. In addition, Eversource recorded $2.0 million in Energy Efficiency expense related to the implementation of new energy efficiency programs as specified in a DPU-approved rate settlement agreement in the fourth quarter of 2020.

GOODWILL

GOODWILL	12 Months Ended
	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL	GOODWILL In a business combination, the excess of the purchase price over the estimated fair values of the assets acquired and liabilities assumed is recognized as goodwill. The following table presents Eversource’s goodwill by reportable segment: (Millions of Dollars) Electric Electric Natural Gas Water Total Balance as of January 1, 2021 $ 2,543.6 $ 576.8 $ 441.4 $ 884.2 $ 4,446.0 CMA Measurement Period Adjustments — — 9.6 — 9.6 Acquisition of NESC — — — 21.7 21.7 Balance as of December 31, 2021 $ 2,543.6 $ 576.8 $ 451.0 $ 905.9 $ 4,477.3 NESC Measurement Period Adjustments — — — 0.5 0.5 Acquisition of TWC — — — 44.8 44.8 Balance as of December 31, 2022 $ 2,543.6 $ 576.8 $ 451.0 $ 951.2 $ 4,522.6 Eversource completed the acquisition of TWC on October 3, 2022, resulting in the addition of $44.8 million of goodwill, all of which was allocated to the Water Distribution reporting unit. Eversource completed the acquisition of NESC on December 1, 2021, resulting in the addition of $22.2 million of goodwill, which included measurement period increases in 2022 totaling $0.5 million. The goodwill was allocated to the Water Distribution reporting unit. Eversource completed the CMA asset acquisition on October 9, 2020, resulting in the addition of $51.9 million of goodwill, which included measurement period adjustments in 2021 resulting in an additional $9.6 million of goodwill. The goodwill was allocated to the Natural Gas Distribution reporting unit. For further information on the acquisitions of TWC and NESC, see Note 18, “Common Shares,” to the financial statements. Goodwill is evaluated for impairment at least annually and more frequently if indicators of impairment arise. In accordance with the accounting standards, if the fair value of a reporting unit is less than its carrying value (including goodwill), the goodwill is tested for impairment. Goodwill is not subject to amortization, however is subject to a fair value based assessment for impairment at least annually and whenever facts or circumstances indicate that there may be an impairment. A resulting write-down, if any, would be charged to Operating Expenses. In assessing goodwill for impairment, an entity is permitted to first assess qualitatively whether it is more likely than not that goodwill impairment exists as of the annual impairment test date. A quantitative impairment test is required only if it is concluded that it is more likely than not that a reporting unit’s fair value is less than it’s carrying amount. The annual goodwill assessment included a qualitative evaluation of multiple factors that impact the fair value of the reporting units, including general, macroeconomic and market conditions, and entity-specific assumptions that affect the future cash flows of the reporting units. Key considerations include discount rates, utility sector market performance and merger transaction multiples, the Company's share price and credit ratings, analyst reports, financial performance, cost and risk factors, internal estimates and projections of future cash flows and net income, long-term strategy, the timing and outcome of rate cases, and recent regulatory and legislative proceedings. Eversource's reporting units for the purpose of testing goodwill are Electric Distribution, Electric Transmission, Natural Gas Distribution and Water Distribution. These reporting units are consistent with the operating segments underlying the reportable segments identified in Note 23, "Segment Information," to the financial statements.

SCHEDULE I - FINANCIAL INFORMAT

SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT	12 Months Ended
	Dec. 31, 2022
Condensed Financial Information Disclosure [Abstract]
SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT	SCHEDULE I EVERSOURCE ENERGY (PARENT) FINANCIAL INFORMATION OF REGISTRANT BALANCE SHEETS AS OF DECEMBER 31, 2022 AND 2021 (Thousands of Dollars) 2022 2021 ASSETS Current Assets: Cash $ 971 $ 175 Accounts Receivable from Subsidiaries 53,338 43,403 Notes Receivable from Subsidiaries 1,074,800 1,245,900 Prepayments and Other Current Assets 23,597 11,974 Total Current Assets 1,152,706 1,301,452 Deferred Debits and Other Assets: Investments in Subsidiary Companies, at Equity 18,379,840 16,108,190 Notes Receivable from Subsidiaries 1,896,500 1,001,000 Accumulated Deferred Income Taxes — 17,409 Goodwill 3,852,524 3,852,524 Other Long-Term Assets 108,867 101,710 Total Deferred Debits and Other Assets 24,237,731 21,080,833 Total Assets $ 25,390,437 $ 22,382,285 LIABILITIES AND CAPITALIZATION Current Liabilities: Notes Payable $ 1,442,200 $ 1,342,950 Long-Term Debt - Current Portion 1,207,047 767,681 Accounts Payable to Subsidiaries 33,530 37,609 Other Current Liabilities 112,807 87,745 Total Current Liabilities 2,795,584 2,235,985 Deferred Credits and Other Liabilities: Accumulated Deferred Income Taxes 8,498 — Other Long-Term Liabilities 140,393 150,616 Total Deferred Credits and Other Liabilities 148,891 150,616 Long-Term Debt 6,972,804 5,395,840 Common Shareholders' Equity: Common Shares 1,799,920 1,789,092 Capital Surplus, Paid in 8,401,731 8,098,514 Retained Earnings 5,527,153 5,005,391 Accumulated Other Comprehensive Loss (39,421) (42,275) Treasury Stock (216,225) (250,878) Common Shareholders' Equity 15,473,158 14,599,844 Total Liabilities and Capitalization $ 25,390,437 $ 22,382,285 See the Combined Notes to Financial Statements in this Annual Report on Form 10-K for a description of significant accounting matters related to Eversource parent, including Eversource common shares information as described in Note 18, "Common Shares," material obligations and guarantees as described in Note 13, "Commitments and Contingencies," and debt agreements as described in Note 8, "Short-Term Debt," and Note 9, "Long-Term Debt." SCHEDULE I EVERSOURCE ENERGY (PARENT) FINANCIAL INFORMATION OF REGISTRANT STATEMENTS OF INCOME FOR THE YEARS ENDED DECEMBER 31, 2022, 2021 AND 2020 (Thousands of Dollars, Except Share Information) 2022 2021 2020 Operating Revenues $ — $ — $ — Operating Expenses: Other 26,708 43,048 28,645 Operating Loss (26,708) (43,048) (28,645) Interest Expense 237,773 163,613 160,887 Other Income, Net: Equity in Earnings of Subsidiaries 1,565,474 1,345,199 1,309,630 Other, Net 79,383 47,802 38,546 Other Income, Net 1,644,857 1,393,001 1,348,176 Income Before Income Tax Benefit 1,380,376 1,186,340 1,158,644 Income Tax Benefit (24,499) (34,187) (46,523) Net Income $ 1,404,875 $ 1,220,527 $ 1,205,167 Basic Earnings per Common Share $ 4.05 $ 3.55 $ 3.56 Diluted Earnings per Common Share $ 4.05 $ 3.54 $ 3.55 Weighted Average Common Shares Outstanding: Basic 346,783,444 343,972,926 338,836,147 Diluted 347,246,768 344,631,056 339,847,062 STATEMENTS OF COMPREHENSIVE INCOME (Thousands of Dollars) 2022 2021 2020 Net Income $ 1,404,875 $ 1,220,527 $ 1,205,167 Other Comprehensive Income/(Loss), Net of Tax: Qualified Cash Flow Hedging Instruments 20 972 1,596 Changes in Unrealized (Losses)/Gains on Marketable Securities (1,636) (671) 342 Changes in Funded Status of Pension, SERP and PBOP Benefit Plans 4,470 33,835 (13,290) Other Comprehensive Income/(Loss), Net of Tax 2,854 34,136 (11,352) Comprehensive Income $ 1,407,729 $ 1,254,663 $ 1,193,815 See the Combined Notes to Financial Statements in this Annual Report on Form 10-K for a description of significant accounting matters related to Eversource parent, including Eversource common shares information as described in Note 18, "Common Shares," material obligations and guarantees as described in Note 13, "Commitments and Contingencies," and debt agreements as described in Note 8, "Short-Term Debt," and Note 9, "Long-Term Debt." SCHEDULE I EVERSOURCE ENERGY (PARENT) FINANCIAL INFORMATION OF REGISTRANT STATEMENTS OF CASH FLOWS FOR THE YEARS ENDED DECEMBER 31, 2022, 2021 and 2020 (Thousands of Dollars) 2022 2021 2020 Operating Activities: Net Income $ 1,404,875 $ 1,220,527 $ 1,205,167 Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities: Equity in Earnings of Subsidiaries (1,565,474) (1,345,199) (1,309,630) Cash Dividends Received from Subsidiaries 855,600 1,037,100 485,800 Deferred Income Taxes 25,823 20,293 (4,667) Other 26,455 36,910 39,940 Changes in Current Assets and Liabilities: Accounts Receivables from Subsidiaries (9,935) (3,758) (14,575) Taxes Receivable/Accrued, Net (21,627) (19,455) 35,300 Accounts Payable to Subsidiaries (4,079) 19,185 14,091 Other Current Assets and Liabilities, Net 35,090 8,144 21,284 Net Cash Flows Provided by Operating Activities 746,728 973,747 472,710 Investing Activities: Capital Contributions to Subsidiaries (1,499,300) (1,033,000) (1,899,340) Return of Capital from Subsidiaries 12,000 178,800 80,000 Increase in Notes Receivable from Subsidiaries (724,400) (140,200) (264,300) Other Investing Activities (1,289) (3,196) (367) Net Cash Flows Used in Investing Activities (2,212,989) (997,596) (2,084,007) Financing Activities: Issuance of Common Shares, Net of Issuance Costs 197,058 — 928,992 Cash Dividends on Common Shares (860,033) (805,439) (744,665) Issuance of Long-Term Debt 2,800,000 1,000,000 1,550,000 Retirement of Long-Term Debt (750,000) (450,000) — Increase/(Decrease) in Notes Payable 99,250 288,625 (170,545) Other Financing Activities (19,193) (9,545) 46,480 Net Cash Flows Provided by Financing Activities 1,467,082 23,641 1,610,262 Net Increase/(Decrease) in Cash and Restricted Cash 821 (208) (1,035) Cash and Restricted Cash - Beginning of Year 226 434 1,469 Cash and Restricted Cash - End of Year $ 1,047 $ 226 $ 434 Supplemental Cash Flow Information: Cash Paid/(Received) During the Year for: Interest $ 215,053 $ 164,568 $ 140,694 Income Taxes $ (20,992) $ (51,277) $ (43,158) See the Combined Notes to Financial Statements in this Annual Report on Form 10-K for a description of significant accounting matters related to Eversource parent, including Eversource common shares information as described in Note 18, "Common Shares," material obligations and guarantees as described in Note 13, "Commitments and Contingencies," and debt agreements as described in Note 8, "Short-Term Debt," and Note 9, "Long-Term Debt."

SCHEDULE II - VALUATION AND QUA

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES	12 Months Ended
	Dec. 31, 2022
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES	SCHEDULE II EVERSOURCE ENERGY AND SUBSIDIARIES VALUATION AND QUALIFYING ACCOUNTS AND RESERVES FOR THE YEARS ENDED DECEMBER 31, 2022, 2021 AND 2020 (Thousands of Dollars) Column A Column B Column C Column D Column E Additions (1) (2) Description: Balance as of Beginning of Year Charged to Costs and Expenses Charged to Other Deductions -Describe (b) Balance as of End of Year Eversource : Reserves Deducted from Assets - Reserves for Uncollectible Accounts: 2022 $ 417,406 $ 61,876 $ 112,533 $ 105,518 $ 486,297 2021 358,851 60,886 110,572 112,903 417,406 2020 224,821 53,461 145,005 64,436 358,851 CL&P: Reserves Deducted from Assets - Reserves for Uncollectible Accounts: 2022 $ 181,319 $ 15,578 $ 59,485 $ 31,062 $ 225,320 2021 157,447 13,495 57,779 47,402 181,319 2020 97,348 12,882 71,223 24,006 157,447 NSTAR Electric: Reserves Deducted from Assets - Reserves for Uncollectible Accounts: 2022 $ 97,005 $ 21,550 $ 12,412 $ 36,009 $ 94,958 2021 91,583 16,649 20,064 31,291 97,005 2020 75,406 15,293 23,424 22,540 91,583 PSNH : Reserves Deducted from Assets - Reserves for Uncollectible Accounts: 2022 $ 24,331 $ 9,211 $ 2,539 $ 6,845 $ 29,236 2021 17,157 13,113 3,135 9,074 24,331 2020 10,497 5,164 7,692 6,196 17,157 (a) Amounts relate to uncollectible accounts receivables reserved for that are not charged to bad debt expense. CL&P, NSTAR Electric, NSTAR Gas, EGMA and Yankee Gas are allowed to recover in rates, amounts associated with certain uncollectible hardship accounts receivable. CL&P, NSTAR Electric, PSNH, NSTAR Gas and EGMA are also allowed to recover uncollectible energy supply costs through regulatory tracking mechanisms. Amounts in this column in 2020 also include a $24.2 million increase due to the CMA asset acquisition on October 9, 2020 at Eversource, and an increase due to the adoption of the credit loss accounting standard in 2020 of $23.8 million at Eversource, $22.2 million at CL&P, $0.3 million at PSNH, and a decrease of $1.3 million at NSTAR Electric.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements of Eversource, NSTAR Electric and PSNH include the accounts of each of their respective subsidiaries. Intercompany transactions have been eliminated in consolidation. The accompanying consolidated financial statements of Eversource, NSTAR Electric and PSNH and the financial statements of CL&P are herein collectively referred to as the "financial statements." The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. CYAPC and YAEC are inactive regional nuclear power companies engaged in the long-term storage of their spent nuclear fuel. Eversource consolidates the operations of CYAPC and YAEC because CL&P's, NSTAR Electric's and PSNH's combined ownership and voting interests in each of these entities is greater than 50 percent. Intercompany transactions between CL&P, NSTAR Electric, PSNH and the CYAPC and YAEC companies have been eliminated in consolidation of the Eversource financial statements. Eversource holds several equity ownership interests that are not consolidated and are accounted for under the equity method. In accordance with accounting guidance on noncontrolling interests in consolidated financial statements, the Preferred Stock of CL&P and the Preferred Stock of NSTAR Electric, which are not owned by Eversource or its consolidated subsidiaries and are not subject to mandatory redemption, have been presented as noncontrolling interests in the financial statements of Eversource. The Preferred Stock of CL&P and the Preferred Stock of NSTAR Electric are considered to be temporary equity and have been classified between liabilities and permanent shareholders' equity on the balance sheets of Eversource, CL&P and NSTAR Electric due to a provision in the preferred stock agreements of both CL&P and NSTAR Electric that grant preferred stockholders the right to elect a majority of the CL&P and NSTAR Electric Boards of Directors, respectively, should certain conditions exist, such as if preferred dividends are in arrears for a specified amount of time. The Net Income reported in the statements of income and cash flows represents net income prior to apportionment to noncontrolling interests, which is represented by dividends on preferred stock of CL&P and NSTAR Electric.
Cash and Cash Equivalents	Cash and Cash EquivalentsCash includes cash on hand. At the end of each reporting period, any overdraft amounts are reclassified from Cash to Accounts Payable on the balance sheets. Cash Equivalents include short-term cash investments that are highly liquid in nature and have original maturities of three months or less.
Provision for Uncollectible Accounts	Allowance for Uncollectible Accounts Receivables, Net on the balance sheets primarily includes trade receivables from retail customers and customers related to wholesale transmission contracts, wholesale market sales, sales of RECs, and property rentals. Receivables, Net also includes customer receivables for the purchase of electricity from a competitive third party supplier, the current portion of customer energy efficiency loans, property damage receivables and other miscellaneous receivables. There is no material concentration of receivables. Receivables are recorded at amortized cost, net of a credit loss provision (or allowance for uncollectible accounts). The current expected credit loss (CECL) model, which was implemented on January 1, 2020 (ASU 2016-13), is applied to receivables for purposes of calculating the allowance for uncollectible accounts. This model is based on expected losses and results in the recognition of estimated expected credit losses, including uncollectible amounts for both billed and unbilled revenues, over the life of the receivable at the time a receivable is recorded. The allowance for uncollectible accounts is determined based upon a variety of judgments and factors, including an aging-based quantitative assessment that applies an estimated uncollectible percentage to each receivable aging category. Factors in determining credit loss include historical collection, write-off experience, analysis of delinquency statistics, and management's assessment of collectability from customers, including current economic conditions, customer payment trends, the impact on customer bills because of energy usage trends and changes in rates, flexible payment plans and financial hardship arrearage management programs being offered to customers, reasonable forecasts, and expectations of future collectability and collection efforts. Management continuously assesses the collectability of receivables and adjusts estimates based on actual experience and future expectations based on economic conditions, collection efforts and other factors. Management also monitors the aging analysis of receivables to determine if there are changes in the collections of accounts receivable. Receivable balances are written off against the allowance for uncollectible accounts when the customer accounts are no longer in service and these balances are deemed to be uncollectible. Management concluded that the reserve balance as of December 31, 2022 adequately reflected the collection risk and net realizable value for its receivables. As of December 31, 2022 and 2021, the total amount incurred as a result of COVID-19 included in the allowance for uncollectible accounts was $50.9 million and $55.3 million at Eversource, $16.0 million and $23.9 million at CL&P, and $4.1 million and $9.0 million at NSTAR Electric, respectively. At our Connecticut and Massachusetts utilities, the COVID-19 related uncollectible amounts were deferred either as incremental regulatory costs or deferred through existing regulatory tracking mechanisms that recover uncollectible energy supply costs, as management believes it is probable that these costs will ultimately be recovered from customers in future rates. No COVID-19 related uncollectible amounts were deferred at PSNH as a result of a July 2021 NHPUC order. Based on the status of our COVID-19 regulatory dockets, policies and practices in the jurisdictions in which we operate, we believe the state regulatory commissions in Connecticut and Massachusetts will allow us to recover our incremental uncollectible customer receivable costs associated with COVID-19.
Transfer of Energy Efficiency Loans	Transfer of Energy Efficiency LoansCL&P transferred a portion of its energy efficiency customer loan portfolio to outside lenders in order to make additional loans to customers.  CL&P remains the servicer of the loans and will transmit customer payments to the lenders, with a maximum amount outstanding under this program of $55 million.  The amounts of the loans are included in Accounts Receivable, Net and Other Long-Term Assets, and are offset by Other Current Liabilities and Other Long-Term Liabilities on CL&P’s balance sheet.
Materials, Supplies, Natural Gas and REC Inventory	Materials, Supplies, Natural Gas and REC InventoryMaterials, Supplies, Natural Gas and REC Inventory include materials and supplies purchased primarily for construction or operation and maintenance purposes, natural gas purchased for delivery to customers, and RECs.  Inventory is valued at the lower of cost or net realizable value. RECs are purchased from suppliers of renewable sources of generation and are used to meet state mandated Renewable Portfolio Standards requirements.
Fair Value Measurements	Fair Value Measurements Fair value measurement guidance is applied to derivative contracts that are not elected or designated as "normal purchases" or "normal sales" (normal) and to marketable securities held in trusts. Fair value measurement guidance is also applied to valuations of the investments used to calculate the funded status of pension and PBOP plans, the nonrecurring fair value measurements of nonfinancial assets such as goodwill, long-lived assets, equity method investments, AROs, and in the valuation of business combinations and asset acquisitions. The fair value measurement guidance was also applied in estimating the fair value of preferred stock, long-term debt and RRBs. Fair Value Hierarchy: In measuring fair value, Eversource uses observable market data when available in order to minimize the use of unobservable inputs. Inputs used in fair value measurements are categorized into three fair value hierarchy levels for disclosure purposes. The entire fair value measurement is categorized based on the lowest level of input that is significant to the fair value measurement. Eversource evaluates the classification of assets and liabilities measured at fair value on a quarterly basis. The levels of the fair value hierarchy are described below: Level 1 - Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 - Inputs are quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which all significant inputs are observable. Level 3 - Quoted market prices are not available. Fair value is derived from valuation techniques in which one or more significant inputs or assumptions are unobservable. Where possible, valuation techniques incorporate observable market inputs that can be validated to external sources such as industry exchanges, including prices of energy and energy-related products. Uncategorized - Investments that are measured at net asset value are not categorized within the fair value hierarchy. Determination of Fair Value: The valuation techniques and inputs used in Eversource's fair value measurements are described in Note 4, "Derivative Instruments," Note 5, "Marketable Securities," Note 6, "Investments in Unconsolidated Affiliates," Note 7, "Asset Retirement Obligations," Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," Note 15, "Fair Value of Financial Instruments," and Note 25, “Goodwill,” to the financial statements.
Derivative Accounting	Derivative Accounting Many of the electric and natural gas companies' contracts for the purchase and sale of energy or energy-related products are derivatives. The accounting treatment for energy contracts entered into varies and depends on the intended use of the particular contract and on whether or not the contract is a derivative. The application of derivative accounting is complex and requires management judgment in the following respects: identification of derivatives and embedded derivatives, election and designation of a contract as normal, and determination of the fair value of derivative contracts. All of these judgments can have a significant impact on the financial statements. The judgment applied in the election of a contract as normal (and resulting accrual accounting) includes the conclusion that it is probable at the inception of the contract and throughout its term that it will result in physical delivery of the underlying product and that the quantities will be used or sold by the business in the normal course of business. If facts and circumstances change and management can no longer support this conclusion, then a contract cannot be considered normal, accrual accounting is terminated, and fair value accounting is applied prospectively. The fair value of derivative contracts is based upon the contract terms and conditions and the underlying market price or fair value per unit. When quantities are not specified in the contract, the Company determines whether the contract has a determinable quantity by using amounts referenced in default provisions and other relevant sections of the contract. The fair value of derivative assets and liabilities with the same counterparty are offset and recorded as a net derivative asset or liability on the balance sheets. Regulatory assets or regulatory liabilities are recorded to offset the fair values of these derivative contracts related to energy and energy-related products, as contract settlements are recovered from, or refunded to, customers in future rates. All changes in the fair value of these derivative contracts are recorded as regulatory assets or liabilities and do not impact net income.
Allowance for Funds Used During Construction	Allowance for Funds Used During ConstructionAFUDC represents the cost of borrowed and equity funds used to finance construction and is included in the cost of the electric, natural gas and water companies' utility plant on the balance sheet.  The portion of AFUDC attributable to borrowed funds is recorded as a reduction of Interest Expense, and the AFUDC related to equity funds is recorded as Other Income, Net on the statements of income.  AFUDC costs are recovered from customers over the service life of the related plant in the form of increased revenue collected as a result of higher depreciation expense. The average AFUDC rate is based on a FERC-prescribed formula using the cost of a company's short-term financings and capitalization (preferred stock, long-term debt and common equity), as appropriate.  The average rate is applied to average eligible CWIP amounts to calculate AFUDC.
Other Taxes	Other TaxesEversource's companies that serve customers in Connecticut collect gross receipts taxes levied by the state of Connecticut from their customers. As agents for state and local governments, Eversource's companies that serve customers in Connecticut and Massachusetts collect certain sales taxes that are recorded on a net basis with no impact on the statements of income.
Related Parties	Related Parties Eversource Service, Eversource's service company, provides centralized accounting, administrative, engineering, financial, information technology, legal, operational, planning, purchasing, tax, and other services to Eversource's companies. The Rocky River Realty Company and Properties, Inc., two other Eversource subsidiaries, construct, acquire or lease some of the property and facilities used by Eversource's companies. As of both December 31, 2022 and 2021, CL&P, NSTAR Electric and PSNH had long-term receivables from Eversource Service in the amounts of $25.0 million, $5.5 million and $3.8 million, respectively, which were included in Other Long-Term Assets on the balance sheets. These amounts related to the funding of investments held in trust by Eversource Service in connection with certain postretirement benefits for CL&P, NSTAR Electric and PSNH employees and have been eliminated in consolidation on the Eversource financial statements. Included in the CL&P, NSTAR Electric and PSNH balance sheets as of December 31, 2022 and 2021 were Accounts Receivable from Affiliated Companies and Accounts Payable to Affiliated Companies relating to transactions between CL&P, NSTAR Electric and PSNH and other subsidiaries that are wholly-owned by Eversource. These amounts have been eliminated in consolidation on the Eversource financial statements. The Eversource Energy Foundation is an independent not-for-profit charitable entity and is not included in the consolidated financial statements of Eversource as the Company does not have title to, and cannot receive contributions back from, the Eversource Energy Foundation's assets. Eversource made contributions to the Eversource Energy Foundation of $8.0 million in 2022 and $6.4 million in 2020 and did not make any contributions in 2021.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Provision for Uncollectible Accounts	The activity in the allowance for uncollectible accounts by portfolio segment is as follows: Eversource CL&P NSTAR Electric PSNH (Millions of Dollars) Hardship Accounts Retail (Non-Hardship), Total Allowance Hardship Accounts Retail (Non-Hardship), Total Allowance Hardship Accounts Retail (Non-Hardship), Total Allowance Total Allowance Balance as of January 1, 2020 $ 143.3 $ 81.5 $ 224.8 $ 80.1 $ 17.2 $ 97.3 $ 43.9 $ 31.5 $ 75.4 $ 10.5 ASU 2016-13 Implementation 21.6 2.2 23.8 21.3 0.9 22.2 (1.6) 0.3 (1.3) 0.3 Increase due to CMA acquisition — 24.2 24.2 — — — — — — — Uncollectible Expense — 53.5 53.5 — 12.9 12.9 — 15.3 15.3 5.2 Uncollectible Costs Deferred (1) 43.1 53.9 97.0 38.2 10.8 49.0 (1.7) 26.4 24.7 7.4 Write-Offs (14.7) (63.3) (78.0) (11.9) (17.8) (29.7) (0.9) (26.3) (27.2) (6.9) Recoveries Collected 1.5 12.1 13.6 1.4 4.3 5.7 — 4.7 4.7 0.7 Balance as of December 31, 2020 $ 194.8 $ 164.1 $ 358.9 $ 129.1 $ 28.3 $ 157.4 $ 39.7 $ 51.9 $ 91.6 $ 17.2 Uncollectible Expense — 60.9 60.9 — 13.5 13.5 — 16.6 16.6 13.1 Uncollectible Costs Deferred (1) 51.9 58.7 110.6 32.3 25.5 57.8 4.3 15.8 20.1 3.1 Write-Offs (22.0) (107.7) (129.7) (18.0) (36.2) (54.2) (0.7) (36.3) (37.0) (10.0) Recoveries Collected 1.4 15.3 16.7 1.2 5.6 6.8 — 5.7 5.7 0.9 Balance as of December 31, 2021 $ 226.1 $ 191.3 $ 417.4 $ 144.6 $ 36.7 $ 181.3 $ 43.3 $ 53.7 $ 97.0 $ 24.3 Uncollectible Expense — 61.9 61.9 — 15.6 15.6 — 21.6 21.6 9.2 Uncollectible Costs Deferred (1) 77.8 34.7 112.5 58.3 1.2 59.5 1.5 10.9 12.4 2.5 Write-Offs (21.3) (102.7) (124.0) (15.3) (23.0) (38.3) (1.1) (41.2) (42.3) (7.7) Recoveries Collected 1.8 16.7 18.5 1.3 5.9 7.2 — 6.3 6.3 0.9 Balance as of December 31, 2022 $ 284.4 $ 201.9 $ 486.3 $ 188.9 $ 36.4 $ 225.3 $ 43.7 $ 51.3 $ 95.0 $ 29.2 (1) These expected credit losses are deferred as regulatory costs on the balance sheets, as these amounts are ultimately recovered in rates. Amounts include uncollectible costs for hardship accounts and other customer receivables, including uncollectible amounts related to uncollectible energy supply costs and COVID-19. The increase in the allowance for uncollectible hardship accounts in 2022 at Eversource and CL&P primarily relates to increased customer enrollment in disconnection prevention programs in Connecticut.
Schedule of Utility Inventory	The carrying amounts of materials and supplies, natural gas inventory, and RECs, which are included in Current Assets on the balance sheets, were as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Materials and Supplies $ 221.0 $ 88.2 $ 81.0 $ 34.4 $ 148.9 $ 60.3 $ 55.0 $ 25.2 Natural Gas 95.9 — — — 56.2 — — — RECs 57.5 — 57.4 0.1 62.4 — 61.7 0.7 Total $ 374.4 $ 88.2 $ 138.4 $ 34.5 $ 267.5 $ 60.3 $ 116.7 $ 25.9
Costs Related to Fuel and Natural Gas	The cost of natural gas included in Purchased Power, Purchased Natural Gas and Transmission on the statements of income were as follows: For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Eversource - Cost of Natural Gas $ 1,010.2 $ 718.6 $ 464.2
Weighted-Average AFUDC Rates	AFUDC costs and the weighted-average AFUDC rates were as follows: Eversource For the Years Ended December 31, (Millions of Dollars, except percentages) 2022 2021 2020 Borrowed Funds $ 21.8 $ 18.4 $ 23.7 Equity Funds 47.3 37.3 42.0 Total AFUDC $ 69.1 $ 55.7 $ 65.7 Average AFUDC Rate 4.7 % 4.2 % 5.0 % For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars, CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Borrowed Funds $ 4.8 $ 10.7 $ 1.4 $ 2.9 $ 9.0 $ 0.8 $ 6.6 $ 9.1 $ 2.1 Equity Funds 13.6 24.6 2.5 7.7 20.4 1.6 13.8 21.5 4.2 Total AFUDC $ 18.4 $ 35.3 $ 3.9 $ 10.6 $ 29.4 $ 2.4 $ 20.4 $ 30.6 $ 6.3 Average AFUDC Rate 6.6 % 5.4 % 2.6 % 5.0 % 4.9 % 2.5 % 5.9 % 5.7 % 4.7 %
Components of Other Income, Net	The components of Other Income, Net on the statements of income were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion (1) $ 219.8 $ 84.4 $ 44.4 AFUDC Equity 47.3 37.3 42.0 Equity in Earnings of Unconsolidated Affiliates (2) 22.9 14.2 14.2 Investment Income/(Loss) 1.9 (0.2) 1.1 Interest Income 50.5 25.6 4.8 Gain on Sale of Property 2.6 0.1 1.8 Other 1.1 (0.1) 0.3 Total Other Income, Net $ 346.1 $ 161.3 $ 108.6 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion (1) $ 64.4 $ 85.5 $ 26.8 $ 15.2 $ 40.2 $ 10.3 $ 3.8 $ 29.3 $ 7.0 AFUDC Equity 13.6 24.6 2.5 7.7 20.4 1.6 13.8 21.5 4.2 Investment (Loss)/Income (1.3) 1.2 0.2 1.3 0.1 0.1 1.1 (0.8) 0.1 Interest Income 6.5 30.7 3.1 5.9 13.4 2.4 2.0 0.9 2.4 Other 0.1 0.7 0.1 0.1 0.7 0.2 0.1 1.1 0.1 Total Other Income, Net $ 83.3 $ 142.7 $ 32.7 $ 30.2 $ 74.8 $ 14.6 $ 20.8 $ 52.0 $ 13.8 (1) See Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," for the components of net periodic benefit income/expense for the Pension, SERP and PBOP Plans. The non-service related components of pension, SERP and PBOP benefit income/expense, after capitalization or deferral, are presented as non-operating income and recorded in Other Income, Net on the statements of income.
Other Taxes	These gross receipts taxes are recorded separately with collections in Operating Revenues and with payments in Taxes Other Than Income Taxes on the statements of income as follows: For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Eversource $ 194.7 $ 181.9 $ 170.6 CL&P 166.1 158.1 149.9
Supplemental Cash Flow Information	Eversource (Millions of Dollars) As of and For the Years Ended December 31, 2022 2021 2020 Cash Paid During the Year for: Interest, Net of Amounts Capitalized $ 636.2 $ 568.7 $ 518.0 Income Taxes 77.9 121.6 48.9 Non-Cash Investing Activities: Plant Additions Included in Accounts Payable (As of) 586.9 467.9 367.2 As of and For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Cash Paid During the Year for: Interest, Net of Amounts Capitalized $ 167.2 $ 152.8 $ 58.3 $ 161.5 $ 141.6 $ 56.5 $ 149.0 $ 129.4 $ 54.5 Income Taxes 117.6 23.8 58.3 38.4 74.2 51.1 10.9 110.7 34.2 Non-Cash Investing Activities: Plant Additions Included in Accounts 131.8 184.3 76.2 110.6 120.0 68.7 101.8 103.2 33.3
Cash and Cash Equivalents as Reported on the Balance Sheet	As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Cash and Cash Equivalents as reported on the $ 374.6 $ 11.3 $ 327.7 $ 0.1 $ 66.8 $ 55.8 $ 0.7 $ — Restricted cash included in: Special Deposits 102.2 8.8 17.5 33.1 78.2 18.7 17.4 31.4 Marketable Securities 25.4 0.2 0.1 0.4 31.3 0.3 0.1 0.5 Other Long-Term Assets 19.6 — — 3.2 44.7 — — 3.2 Cash, Cash Equivalents and Restricted Cash $ 521.8 $ 20.3 $ 345.3 $ 36.8 $ 221.0 $ 74.8 $ 18.2 $ 35.1

REGULATORY ACCOUNTING (Tables)

REGULATORY ACCOUNTING (Tables)	12 Months Ended
	Dec. 31, 2022
Regulated Operations [Abstract]
Components of Regulatory Assets	The components of regulatory assets were as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Benefit Costs $ 921.7 $ 156.7 $ 299.5 $ 56.6 $ 1,481.0 $ 272.4 $ 395.5 $ 118.9 Storm Costs, Net 1,379.1 799.3 484.4 95.4 1,102.7 695.6 341.3 65.8 Regulatory Tracking Mechanisms 1,075.3 216.8 391.5 73.7 1,050.5 333.6 376.6 85.4 Income Taxes, Net 853.3 491.1 115.6 16.0 790.7 470.5 112.6 17.5 Securitized Stranded Costs 435.7 — — 435.7 478.9 — — 478.9 Goodwill-related 281.0 — 241.2 — 297.8 — 255.7 — Derivative Liabilities 181.8 181.8 — — 249.2 249.2 — — Asset Retirement Obligations 127.9 35.9 68.2 4.4 115.0 33.6 59.8 4.1 Other Regulatory Assets 322.5 26.2 114.0 14.4 150.0 29.9 37.7 15.8 Total Regulatory Assets 5,578.3 1,907.8 1,714.4 696.2 5,715.8 2,084.8 1,579.2 786.4 Less: Current Portion 1,335.5 314.1 492.8 102.2 1,129.1 371.6 444.0 107.2 Total Long-Term Regulatory Assets $ 4,242.8 $ 1,593.7 $ 1,221.6 $ 594.0 $ 4,586.7 $ 1,713.2 $ 1,135.2 $ 679.2
Components of Regulatory Liabilities	The components of regulatory liabilities were as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH EDIT due to Tax Cuts and Jobs Act of 2017 $ 2,619.3 $ 983.6 $ 944.3 $ 348.6 $ 2,685.2 $ 996.1 $ 984.5 $ 359.2 Cost of Removal 670.6 130.8 405.3 14.7 649.6 100.1 381.0 17.2 Regulatory Tracking Mechanisms 890.8 361.0 336.1 155.0 448.4 182.0 185.1 107.0 Deferred Portion of Non-Service Income 270.9 34.5 139.7 28.8 148.3 12.0 90.7 14.9 Benefit Costs 55.4 0.7 31.4 — 133.5 — 107.4 — AFUDC - Transmission 98.2 48.2 50.0 — 81.0 43.2 37.8 — CL&P Settlement Agreement and Storm — — — — 81.3 81.3 — — Other Regulatory Liabilities 215.9 40.6 14.5 6.5 241.4 45.1 0.8 3.3 Total Regulatory Liabilities 4,821.1 1,599.4 1,921.3 553.6 4,468.7 1,459.8 1,787.3 501.6 Less: Current Portion 890.8 336.0 373.2 162.0 602.4 266.5 228.2 120.2 Total Long-Term Regulatory Liabilities $ 3,930.3 $ 1,263.4 $ 1,548.1 $ 391.6 $ 3,866.3 $ 1,193.3 $ 1,559.1 $ 381.4

PROPERTY, PLANT AND EQUIPMENT_2

PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION (Tables)	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Schedule of Utility Property, Plant and Equipment	The following tables summarize property, plant and equipment by asset category: Eversource As of December 31, (Millions of Dollars) 2022 2021 Distribution - Electric $ 18,326.2 $ 17,679.1 Distribution - Natural Gas 7,443.8 6,694.8 Transmission - Electric 13,709.3 12,882.4 Distribution - Water 2,112.6 1,900.9 Solar 200.8 200.9 Utility 41,792.7 39,358.1 Other (1) 1,738.1 1,469.5 Property, Plant and Equipment, Gross 43,530.8 40,827.6 Less: Accumulated Depreciation Utility (9,167.4) (8,885.2) Other (706.1) (580.1) Total Accumulated Depreciation (9,873.5) (9,465.3) Property, Plant and Equipment, Net 33,657.3 31,362.3 Construction Work in Progress 2,455.5 2,015.4 Total Property, Plant and Equipment, Net $ 36,112.8 $ 33,377.7 As of December 31, 2022 2021 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH Distribution - Electric $ 7,370.1 $ 8,410.0 $ 2,586.4 $ 7,117.6 $ 8,105.5 $ 2,496.2 Transmission - Electric 6,165.1 5,333.8 2,212.0 5,859.0 5,090.5 1,934.6 Solar — 200.8 — — 200.9 — Property, Plant and Equipment, Gross 13,535.2 13,944.6 4,798.4 12,976.6 13,396.9 4,430.8 Less: Accumulated Depreciation (2,567.1) (3,381.2) (912.3) (2,572.1) (3,227.3) (908.4) Property, Plant and Equipment, Net 10,968.1 10,563.4 3,886.1 10,404.5 10,169.6 3,522.4 Construction Work in Progress 498.9 1,063.6 174.1 399.0 707.0 134.1 Total Property, Plant and Equipment, Net $ 11,467.0 $ 11,627.0 $ 4,060.2 $ 10,803.5 $ 10,876.6 $ 3,656.5 (1) These assets are primarily comprised of computer software, hardware and equipment at Eversource Service and buildings at The Rocky River Realty Company. The depreciation rates for the various classes of utility property, plant and equipment aggregate to composite rates as follows: (Percent) 2022 2021 2020 Eversource 3.0 % 3.1 % 3.0 % CL&P 2.8 % 2.8 % 2.8 % NSTAR Electric 2.7 % 2.8 % 2.8 % PSNH 3.0 % 3.1 % 2.8 % The following table summarizes average remaining useful lives of depreciable assets: As of December 31, 2022 (Years) Eversource CL&P NSTAR Electric PSNH Distribution - Electric 34.2 35.0 34.6 30.8 Distribution - Natural Gas 37.4 — — — Transmission - Electric 39.8 36.3 45.2 39.3 Distribution - Water 39.0 — — — Solar 22.9 — 22.9 — Other (1) 11.0 — — — (1) The estimated useful life of computer software, hardware and equipment primarily ranges from 5 to 15 years and of buildings is 40 years.

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table presents the gross fair values of contracts, categorized by risk type, and the net amounts recorded as current or long-term derivative assets or liabilities: As of December 31, 2022 2021 CL&P (Millions of Dollars) Fair Value Hierarchy Commodity Supply Netting (1) Net Amount Commodity Supply Netting (1) Net Amount Current Derivative Assets Level 3 $ 16.3 $ (0.5) $ 15.8 $ 14.7 $ (1.0) $ 13.7 Long-Term Derivative Assets Level 3 28.8 (0.9) 27.9 46.9 (0.9) 46.0 Current Derivative Liabilities Level 3 (81.6) — (81.6) (73.5) — (73.5) Long-Term Derivative Liabilities Level 3 (143.9) — (143.9) (235.4) — (235.4) (1) Amounts represent derivative assets and liabilities that Eversource elected to record net on the balance sheets. These amounts are subject to master netting agreements or similar agreements for which the right of offset exists.
Fair Value Inputs, Liabilities, Quantitative Information	As of December 31, 2022 2021 CL&P Range Average Period Covered Range Average Period Covered Forward Reserve Prices $ 0.44 — $0.50 $ 0.47 per kW-Month 2023 - 2024 $ 0.50 — $1.15 $ 0.82 per kW-Month 2022 - 2024
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation	The following table presents changes in the Level 3 category of derivative assets and derivative liabilities measured at fair value on a recurring basis. The derivative assets and liabilities are presented on a net basis. CL&P (Millions of Dollars) For the Years Ended December 31, 2022 2021 Derivatives, Net: Fair Value as of Beginning of Period $ (249.2) $ (293.1) Net Realized/Unrealized Gains/(Losses) Included in Regulatory Assets 10.1 (8.5) Settlements 57.3 52.4 Fair Value as of End of Period $ (181.8) $ (249.2)

MARKETABLE SECURITIES (Tables)

MARKETABLE SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities Reconciliation	The following is a summary of the available-for-sale debt securities: As of December 31, 2022 2021 Eversource (Millions of Dollars) Amortized Pre-Tax Pre-Tax Fair Value Amortized Pre-Tax Pre-Tax Fair Value Debt Securities $ 201.6 $ 0.1 $ (16.2) $ 185.5 $ 214.5 $ 5.1 $ (0.2) $ 219.4
Investments Classified by Contractual Maturity Date	As of December 31, 2022, the contractual maturities of available-for-sale debt securities were as follows: Eversource (Millions of Dollars) Amortized Fair Less than one year (1) $ 28.5 $ 28.3 One to five years 43.8 42.4 Six to ten years 35.6 32.3 Greater than ten years 93.7 82.5 Total Debt Securities $ 201.6 $ 185.5 (1) Amounts in the Less than one year category include securities in the CYAPC and YAEC spent nuclear fuel trusts, which are restricted and are classified in long-term Marketable Securities on the balance sheets.
Marketable Securities Recorded at Fair Value	The following table presents the marketable securities recorded at fair value on a recurring basis by the level in which they are classified within the fair value hierarchy: Eversource (Millions of Dollars) As of December 31, 2022 2021 Level 1: Mutual Funds and Equities $ 190.1 $ 254.2 Money Market Funds 25.4 31.3 Total Level 1 $ 215.5 $ 285.5 Level 2: U.S. Government Issued Debt Securities (Agency and Treasury) $ 82.3 $ 81.3 Corporate Debt Securities 46.1 65.3 Asset-Backed Debt Securities 8.6 12.6 Municipal Bonds 12.7 12.3 Other Fixed Income Securities 10.4 16.6 Total Level 2 $ 160.1 $ 188.1 Total Marketable Securities $ 375.6 $ 473.6

INVESTMENTS IN UNCONSOLIDATED_2

INVESTMENTS IN UNCONSOLIDATED AFFILIATES (Tables)	12 Months Ended
	Dec. 31, 2022
Equity Method Investments and Joint Ventures [Abstract]
Summary of Investments	Eversource's investments included the following: Investment Balance as of December 31, (Millions of Dollars) Ownership Interest 2022 2021 Offshore Wind Business - North East Offshore 50 % $ 1,947.1 $ 1,213.6 Natural Gas Pipeline - Algonquin Gas Transmission, LLC 15 % 118.8 121.9 Renewable Energy Investment Fund 90 % 84.1 76.5 Other various 26.1 24.3 Total Investments in Unconsolidated Affiliates $ 2,176.1 $ 1,436.3

ASSET RETIREMENT OBLIGATIONS (T

ASSET RETIREMENT OBLIGATIONS (Tables)	12 Months Ended
	Dec. 31, 2022
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Change in Asset Retirement Obligation	A reconciliation of the beginning and ending carrying amounts of ARO liabilities is as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Balance as of Beginning of Year $ 500.1 $ 35.0 $ 97.5 $ 4.7 $ 499.7 $ 33.4 $ 91.8 $ 4.4 Liabilities Settled During the Year (22.3) — — — (23.9) (0.6) — — Accretion 28.9 2.4 4.1 0.2 29.4 2.2 4.0 0.3 Revisions in Estimated Cash Flows (4.0) — (0.3) — (5.1) — 1.7 — Balance as of End of Year $ 502.7 $ 37.4 $ 101.3 $ 4.9 $ 500.1 $ 35.0 $ 97.5 $ 4.7

SHORT-TERM DEBT (Tables)

SHORT-TERM DEBT (Tables)	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Schedule of Borrowings Outstanding	The amount of borrowings outstanding and available under the commercial paper programs were as follows: Borrowings Outstanding Available Borrowing Capacity as of December 31, Weighted-Average Interest Rate as of December 31, (Millions of Dollars) 2022 2021 2022 2021 2022 2021 Eversource Parent Commercial Paper Program $ 1,442.2 $ 1,343.0 $ 557.8 $ 657.0 4.63 % 0.31 % NSTAR Electric Commercial Paper Program — 162.5 650.0 487.5 — % 0.14 % Details of long-term debt outstanding are as follows: CL&P (Millions of Dollars) As of December 31, Interest Rate 2022 2021 First Mortgage Bonds: 1994 Series D due 2024 7.875 % $ 139.8 $ 139.8 2004 Series B due 2034 5.750 % 130.0 130.0 2005 Series B due 2035 5.625 % 100.0 100.0 2006 Series A due 2036 6.350 % 250.0 250.0 2007 Series B due 2037 5.750 % 150.0 150.0 2007 Series D due 2037 6.375 % 100.0 100.0 2013 Series A due 2023 2.500 % 400.0 400.0 2014 Series A due 2044 4.300 % 475.0 475.0 2015 Series A due 2045 4.150 % 350.0 350.0 2017 Series A due 2027 3.200 % 500.0 500.0 2018 Series A due 2048 4.000 % 800.0 800.0 2020 Series A due 2025 0.750 % 400.0 400.0 2021 Series A due 2031 2.050 % 425.0 425.0 Total First Mortgage Bonds 4,219.8 4,219.8 Less Amounts due Within One Year (400.0) — Current Portion Classified as Long-Term Debt (1) 400.0 — Unamortized Premiums and Discounts, Net 21.5 23.1 Unamortized Debt Issuance Costs (24.8) (27.5) CL&P Long-Term Debt $ 4,216.5 $ 4,215.4 NSTAR Electric (Millions of Dollars) As of December 31, Interest Rate 2022 2021 Debentures: 2006 Debentures due 2036 5.750 % $ 200.0 $ 200.0 2010 Debentures due 2040 5.500 % 300.0 300.0 2012 Debentures due 2022 2.375 % — 400.0 2014 Debentures due 2044 4.400 % 300.0 300.0 2015 Debentures due 2025 3.250 % 250.0 250.0 2016 Debentures due 2026 2.700 % 250.0 250.0 2017 Debentures due 2027 3.200 % 700.0 700.0 2019 Debentures due 2029 3.250 % 400.0 400.0 2020 Debentures due 2030 3.950 % 400.0 400.0 2021 Debentures due 2051 3.100 % 300.0 300.0 2021 Debentures due 2031 1.950 % 300.0 300.0 2022 Debentures due 2052 4.550 % 450.0 — 2022 Debentures due 2052 4.950 % 400.0 — Total Debentures 4,250.0 3,800.0 Notes: 2004 Senior Notes Series B due 2034 5.900 % 50.0 50.0 2007 Senior Notes Series D due 2037 6.700 % 40.0 40.0 2013 Senior Notes Series G due 2023 3.880 % 80.0 80.0 2016 Senior Notes Series H due 2026 2.750 % 50.0 50.0 Total Notes 220.0 220.0 Less Amounts due Within One Year (80.0) (400.0) Unamortized Premiums and Discounts, Net (14.8) (11.2) Unamortized Debt Issuance Costs (30.1) (23.4) NSTAR Electric Long-Term Debt $ 4,345.1 $ 3,585.4 PSNH (Millions of Dollars) As of December 31, Interest Rate 2022 2021 First Mortgage Bonds: 2005 Series M due 2035 5.600 % $ 50.0 $ 50.0 2013 Series S due 2023 3.500 % 325.0 325.0 2019 Series T due 2049 3.600 % 300.0 300.0 2020 Series U due 2050 2.400 % 150.0 150.0 2021 Series V due 2031 2.200 % 350.0 350.0 Total First Mortgage Bonds 1,175.0 1,175.0 Less Amounts due Within One Year (325.0) — Current Portion Classified as Long-Term Debt (1) 295.3 — Unamortized Premiums and Discounts, Net (2.5) (2.6) Unamortized Debt Issuance Costs (7.9) (8.6) PSNH Long-Term Debt $ 1,134.9 $ 1,163.8 OTHER (Millions of Dollars) As of December 31, Interest Rate 2022 2021 Yankee Gas - First Mortgage Bonds due 2024 - 2051 1.380 % - 5.350% $ 845.0 $ 765.0 NSTAR Gas - First Mortgage Bonds due 2025 - 2051 2.250 % - 7.110% 705.0 580.0 EGMA - First Mortgage Bonds due 2031 - 2052 2.110 % - 4.700% 650.0 550.0 Aquarion - Senior Notes due 2024 4.000% 360.0 360.0 Aquarion - Unsecured Notes due 2023 - 2052 — % - 6.430% 464.7 394.9 Aquarion - Secured Debt due 2023 - 2044 2.864 % - 9.290% 34.4 39.6 Eversource Parent - Senior Notes due 2023 - 2050 0.800 % - 4.600% 8,150.0 6,100.0 Pre-1983 Spent Nuclear Fuel Obligation (CYAPC) 11.9 11.7 Fair Value Adjustment (2) 26.2 43.8 Less Fair Value Adjustment - Current Portion (2) (7.0) (17.7) Less Amounts due in One Year (1,203.4) (775.4) Unamortized Premiums and Discounts, Net 40.1 43.4 Unamortized Debt Issuance Costs (49.4) (36.3) Total Other Long-Term Debt $ 10,027.5 $ 8,059.0 Total Eversource Long-Term Debt $ 19,724.0 $ 17,023.6 (1) As a result of the CL&P and PSNH long-term debt issuances in January 2023, $400 million and $295.3 million, respectively, of current portion of long-term debt were reclassified as Long-Term Debt on CL&P’s and PSNH’s balance sheets as of December 31, 2022. (2) The fair value adjustment amount is the purchase price adjustments, net of amortization, required to record long-term debt at fair value on the dates of the 2012 merger with NSTAR and the 2017 acquisition of Aquarion.

LONG-TERM DEBT (Tables)

LONG-TERM DEBT (Tables)	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Schedule of Outstanding Long-Term Debt	The amount of borrowings outstanding and available under the commercial paper programs were as follows: Borrowings Outstanding Available Borrowing Capacity as of December 31, Weighted-Average Interest Rate as of December 31, (Millions of Dollars) 2022 2021 2022 2021 2022 2021 Eversource Parent Commercial Paper Program $ 1,442.2 $ 1,343.0 $ 557.8 $ 657.0 4.63 % 0.31 % NSTAR Electric Commercial Paper Program — 162.5 650.0 487.5 — % 0.14 % Details of long-term debt outstanding are as follows: CL&P (Millions of Dollars) As of December 31, Interest Rate 2022 2021 First Mortgage Bonds: 1994 Series D due 2024 7.875 % $ 139.8 $ 139.8 2004 Series B due 2034 5.750 % 130.0 130.0 2005 Series B due 2035 5.625 % 100.0 100.0 2006 Series A due 2036 6.350 % 250.0 250.0 2007 Series B due 2037 5.750 % 150.0 150.0 2007 Series D due 2037 6.375 % 100.0 100.0 2013 Series A due 2023 2.500 % 400.0 400.0 2014 Series A due 2044 4.300 % 475.0 475.0 2015 Series A due 2045 4.150 % 350.0 350.0 2017 Series A due 2027 3.200 % 500.0 500.0 2018 Series A due 2048 4.000 % 800.0 800.0 2020 Series A due 2025 0.750 % 400.0 400.0 2021 Series A due 2031 2.050 % 425.0 425.0 Total First Mortgage Bonds 4,219.8 4,219.8 Less Amounts due Within One Year (400.0) — Current Portion Classified as Long-Term Debt (1) 400.0 — Unamortized Premiums and Discounts, Net 21.5 23.1 Unamortized Debt Issuance Costs (24.8) (27.5) CL&P Long-Term Debt $ 4,216.5 $ 4,215.4 NSTAR Electric (Millions of Dollars) As of December 31, Interest Rate 2022 2021 Debentures: 2006 Debentures due 2036 5.750 % $ 200.0 $ 200.0 2010 Debentures due 2040 5.500 % 300.0 300.0 2012 Debentures due 2022 2.375 % — 400.0 2014 Debentures due 2044 4.400 % 300.0 300.0 2015 Debentures due 2025 3.250 % 250.0 250.0 2016 Debentures due 2026 2.700 % 250.0 250.0 2017 Debentures due 2027 3.200 % 700.0 700.0 2019 Debentures due 2029 3.250 % 400.0 400.0 2020 Debentures due 2030 3.950 % 400.0 400.0 2021 Debentures due 2051 3.100 % 300.0 300.0 2021 Debentures due 2031 1.950 % 300.0 300.0 2022 Debentures due 2052 4.550 % 450.0 — 2022 Debentures due 2052 4.950 % 400.0 — Total Debentures 4,250.0 3,800.0 Notes: 2004 Senior Notes Series B due 2034 5.900 % 50.0 50.0 2007 Senior Notes Series D due 2037 6.700 % 40.0 40.0 2013 Senior Notes Series G due 2023 3.880 % 80.0 80.0 2016 Senior Notes Series H due 2026 2.750 % 50.0 50.0 Total Notes 220.0 220.0 Less Amounts due Within One Year (80.0) (400.0) Unamortized Premiums and Discounts, Net (14.8) (11.2) Unamortized Debt Issuance Costs (30.1) (23.4) NSTAR Electric Long-Term Debt $ 4,345.1 $ 3,585.4 PSNH (Millions of Dollars) As of December 31, Interest Rate 2022 2021 First Mortgage Bonds: 2005 Series M due 2035 5.600 % $ 50.0 $ 50.0 2013 Series S due 2023 3.500 % 325.0 325.0 2019 Series T due 2049 3.600 % 300.0 300.0 2020 Series U due 2050 2.400 % 150.0 150.0 2021 Series V due 2031 2.200 % 350.0 350.0 Total First Mortgage Bonds 1,175.0 1,175.0 Less Amounts due Within One Year (325.0) — Current Portion Classified as Long-Term Debt (1) 295.3 — Unamortized Premiums and Discounts, Net (2.5) (2.6) Unamortized Debt Issuance Costs (7.9) (8.6) PSNH Long-Term Debt $ 1,134.9 $ 1,163.8 OTHER (Millions of Dollars) As of December 31, Interest Rate 2022 2021 Yankee Gas - First Mortgage Bonds due 2024 - 2051 1.380 % - 5.350% $ 845.0 $ 765.0 NSTAR Gas - First Mortgage Bonds due 2025 - 2051 2.250 % - 7.110% 705.0 580.0 EGMA - First Mortgage Bonds due 2031 - 2052 2.110 % - 4.700% 650.0 550.0 Aquarion - Senior Notes due 2024 4.000% 360.0 360.0 Aquarion - Unsecured Notes due 2023 - 2052 — % - 6.430% 464.7 394.9 Aquarion - Secured Debt due 2023 - 2044 2.864 % - 9.290% 34.4 39.6 Eversource Parent - Senior Notes due 2023 - 2050 0.800 % - 4.600% 8,150.0 6,100.0 Pre-1983 Spent Nuclear Fuel Obligation (CYAPC) 11.9 11.7 Fair Value Adjustment (2) 26.2 43.8 Less Fair Value Adjustment - Current Portion (2) (7.0) (17.7) Less Amounts due in One Year (1,203.4) (775.4) Unamortized Premiums and Discounts, Net 40.1 43.4 Unamortized Debt Issuance Costs (49.4) (36.3) Total Other Long-Term Debt $ 10,027.5 $ 8,059.0 Total Eversource Long-Term Debt $ 19,724.0 $ 17,023.6 (1) As a result of the CL&P and PSNH long-term debt issuances in January 2023, $400 million and $295.3 million, respectively, of current portion of long-term debt were reclassified as Long-Term Debt on CL&P’s and PSNH’s balance sheets as of December 31, 2022. (2) The fair value adjustment amount is the purchase price adjustments, net of amortization, required to record long-term debt at fair value on the dates of the 2012 merger with NSTAR and the 2017 acquisition of Aquarion.
Schedule of Issuance and Repayments of Long-Term Debt	The following table summarizes long-term debt issuances and repayments: (Millions of Dollars) Interest Rate Issuance/ Issue Date or Repayment Date Maturity Date Use of Proceeds for Issuance/ CL&P 2023 Series A First Mortgage Bonds 5.25 % $ 500.0 January 2023 January 2053 Repaid 2013 Series A Bonds at maturity and short-term debt, and paid capital expenditures and working capital CL&P 2013 Series A First Mortgage Bonds 2.50 % (400.0) January 2023 January 2023 Paid at maturity NSTAR Electric 2022 Debentures 4.55 % 450.0 May 2022 June 2052 Repaid short-term debt, paid capital expenditures and working capital NSTAR Electric 2022 Debentures 4.95 % 400.0 September 2022 September 2052 Refinanced investments in eligible green expenditures, which were previously financed using short-term debt from October 1, 2020 through June 30, 2022 NSTAR Electric 2012 Debentures 2.375 % (400.0) October 2022 October 2022 Paid at maturity PSNH Series W First Mortgage Bonds 5.15 % 300.0 January 2023 January 2053 Repaid short-term debt, paid capital expenditures and working capital Eversource Parent Series V Senior Notes 2.90 % 650.0 February 2022 March 2027 Repaid Series K Senior Notes at maturity and short-term debt Eversource Parent Series W Senior Notes 3.375 % 650.0 February 2022 March 2032 Repaid Series K Senior Notes at maturity and short-term debt Eversource Parent Series X Senior Notes 4.20 % 900.0 June 2022 June 2024 Repaid short-term debt and paid working capital Eversource Parent Series Y Senior Notes 4.60 % 600.0 June 2022 July 2027 Repaid short-term debt and paid working capital Eversource Parent Series K Senior Notes 2.75 % (750.0) March 2022 March 2022 Paid at maturity Yankee Gas Series B First Mortgage Bonds 8.48 % (20.0) March 2022 March 2022 Paid at maturity Yankee Gas Series U First Mortgage Bonds 4.31 % 100.0 September 2022 September 2032 Repaid short-term debt, paid capital expenditures and for general corporate purposes EGMA Series C First Mortgage Bonds 4.70 % 100.0 June 2022 June 2052 Repaid short-term debt, paid capital expenditures and for general corporate purposes NSTAR Gas Series V First Mortgage Bonds 4.40 % 125.0 July 2022 August 2032 Repaid short-term debt, paid capital expenditures and for general corporate purposes Aquarion Water Company of New Hampshire General Mortgage Bonds 4.45 % (5.0) July 2022 July 2022 Paid at maturity Aquarion Water Company of Connecticut Senior Notes 4.69 % 70.0 August 2022 September 2052 Repaid short-term debt
Schedule of Maturities of Long-Term Debt Outstanding	Long-term debt maturities on debt outstanding for the years 2023 through 2027 and thereafter are shown below. These amounts exclude PSNH rate reduction bonds, CYAPC pre-1983 spent nuclear fuel obligation, net unamortized premiums, discounts and debt issuance costs, and other fair value adjustments as of December 31, 2022: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2023 $ 2,008.4 $ 400.0 $ 80.0 $ 325.0 2024 1,950.0 139.8 — — 2025 1,400.2 400.0 250.0 — 2026 940.2 — 300.0 — 2027 2,539.2 500.0 700.0 — Thereafter 12,236.0 2,780.0 3,140.0 850.0 Total $ 21,074.0 $ 4,219.8 $ 4,470.0 $ 1,175.0

RATE REDUCTION BONDS AND VARI_2

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES (Tables)	12 Months Ended
	Dec. 31, 2022
Rate Reduction Bonds and Variable Interest Entity [Abstract]
Summary of the Impact of Funding on the Balance Sheets and Income Statements	The following tables summarize the impact of PSNH Funding on PSNH's balance sheets and income statements: (Millions of Dollars) As of December 31, PSNH Balance Sheets: 2022 2021 Restricted Cash - Current Portion (included in Current Assets) $ 32.4 $ 31.1 Restricted Cash - Long-Term Portion (included in Other Long-Term Assets) 3.2 3.2 Securitized Stranded Cost (included in Regulatory Assets) 435.7 478.9 Other Regulatory Liabilities (included in Regulatory Liabilities) 6.0 5.4 Accrued Interest (included in Other Current Liabilities) 6.9 7.5 Rate Reduction Bonds - Current Portion 43.2 43.2 Rate Reduction Bonds - Long-Term Portion 410.5 453.7 (Millions of Dollars) PSNH Income Statements: For the Years Ended December 31, 2022 2021 2020 Amortization of RRB Principal (included in Amortization of Regulatory Assets, Net) $ 43.2 $ 43.2 $ 43.2 Interest Expense on RRB Principal (included in Interest Expense) 17.0 18.4 19.7
Schedule Of Rate Reduction Bonds, Principal And Interest Payments	Estimated principal payments on RRBs as of December 31, 2022, is summarized annually through 2027 and thereafter as follows: (Millions of Dollars) 2023 2024 2025 2026 2027 Thereafter Total PSNH $ 43.2 $ 43.2 $ 43.2 $ 43.2 $ 43.2 $ 237.7 $ 453.7

EMPLOYEE BENEFITS (Tables)

EMPLOYEE BENEFITS (Tables)	12 Months Ended
	Dec. 31, 2022
Postemployment Benefits [Abstract]
Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets	The following tables provide information on the plan benefit obligations, fair values of plan assets, and funded status: Pension and SERP As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Change in Benefit Obligation: Benefit Obligation as of Beginning of Year $ (6,729.7) $ (1,330.9) $ (1,448.4) $ (721.0) $ (7,045.3) $ (1,477.3) $ (1,517.9) $ (748.7) Service Cost (70.1) (18.7) (13.8) (6.9) (85.8) (23.0) (15.8) (8.9) Interest Cost (154.5) (31.3) (32.8) (16.9) (130.0) (27.3) (26.8) (14.5) Actuarial Gain 1,385.8 284.1 295.5 156.7 177.1 127.8 20.8 14.7 Benefits Paid - Pension 302.5 63.3 68.4 33.9 309.5 64.6 68.7 34.7 Benefits Paid - Lump Sum 33.0 — 14.8 1.0 34.7 — 15.6 — Benefits Paid - SERP 12.9 0.3 0.2 0.4 10.1 0.3 0.2 0.4 Employee Transfers — 3.2 5.7 (3.4) — 4.0 6.8 1.3 Benefit Obligation as of End of Year $ (5,220.1) $ (1,030.0) $ (1,110.4) $ (556.2) $ (6,729.7) $ (1,330.9) $ (1,448.4) $ (721.0) Change in Pension Plan Assets: Fair Value of Pension Plan Assets as of $ 6,495.5 $ 1,323.8 $ 1,596.0 $ 694.6 $ 5,409.2 $ 1,043.1 $ 1,345.1 $ 593.7 Employer Contributions 80.0 — 15.0 — 180.0 98.9 30.0 — Actual Return on Pension Plan Assets (433.6) (85.3) (103.3) (45.1) 1,250.5 250.4 312.0 136.9 Benefits Paid - Pension (302.5) (63.3) (68.4) (33.9) (309.5) (64.6) (68.7) (34.7) Benefits Paid - Lump Sum (33.0) — (14.8) (1.0) (34.7) — (15.6) — Employee Transfers — (3.2) (5.7) 3.4 — (4.0) (6.8) (1.3) Fair Value of Pension Plan Assets as of End of Year $ 5,806.4 $ 1,172.0 $ 1,418.8 $ 618.0 $ 6,495.5 $ 1,323.8 $ 1,596.0 $ 694.6 Funded Status as of December 31st $ 586.3 $ 142.0 $ 308.4 $ 61.8 $ (234.2) $ (7.1) $ 147.6 $ (26.4) PBOP As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Change in Benefit Obligation: Benefit Obligation as of Beginning of Year $ (884.3) $ (165.5) $ (238.4) $ (92.3) $ (993.9) $ (178.6) $ (260.5) $ (109.5) Service Cost (11.6) (2.0) (2.0) (1.1) (13.5) (2.3) (2.4) (1.2) Interest Cost (20.2) (3.7) (5.3) (2.2) (17.4) (3.2) (4.4) (1.8) Actuarial Gain 173.6 33.0 39.4 15.2 81.4 5.8 11.5 14.6 Benefits Paid 52.1 10.4 16.6 6.0 51.7 10.9 16.3 5.6 Employee Transfers — (0.1) 0.2 (0.2) — 1.9 1.1 — Impact of Acquisitions (3.3) — — — 7.4 — — — Benefit Obligation as of End of Year $ (693.7) $ (127.9) $ (189.5) $ (74.6) $ (884.3) $ (165.5) $ (238.4) $ (92.3) Change in Plan Assets: Fair Value of Plan Assets as of Beginning of Year $ 1,138.3 $ 145.7 $ 530.0 $ 88.0 $ 1,004.1 $ 134.1 $ 464.6 $ 79.4 Actual Return on Plan Assets (119.6) (15.0) (57.0) (9.8) 183.2 24.1 84.2 14.2 Employer Contributions 3.1 — — — 2.3 — — — Benefits Paid (51.7) (10.4) (16.6) (6.0) (51.3) (10.9) (16.3) (5.6) Employee Transfers — 0.3 (0.3) 0.1 — (1.6) (2.5) — Fair Value of Plan Assets as of End of Year $ 970.1 $ 120.6 $ 456.1 $ 72.3 $ 1,138.3 $ 145.7 $ 530.0 $ 88.0 Funded Status as of December 31st $ 276.4 $ (7.3) $ 266.6 $ (2.3) $ 254.0 $ (19.8) $ 291.6 $ (4.3)
Schedule of Defined Benefit Plans	As of December 31, 2022 and 2021, the accumulated benefit obligation for the Pension and SERP Plans is as follows: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2022 $ 4,911.6 $ 960.7 $ 1,055.1 $ 516.9 2021 6,337.3 1,241.1 1,376.1 670.3 A reconciliation of the prepaid assets and liabilities within the Eversource Pension, SERP and PBOP Plans’ funded status to the balance sheets is as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Prepaid Pension $ 756.7 $ 147.9 $ 310.2 $ 66.4 $ — $ 0.4 $ 149.8 $ — Prepaid PBOP 288.8 — 266.6 — 272.0 — 291.6 — Prepaid Pension and PBOP $ 1,045.5 $ 147.9 $ 576.8 $ 66.4 $ 272.0 $ 0.4 $ 441.4 $ — Accrued Pension $ 3.7 $ — $ — $ — $ 58.1 $ — $ — $ 20.6 Accrued SERP 166.7 5.9 1.8 4.6 176.1 7.5 2.2 5.8 Accrued PBOP 12.4 7.3 — 2.3 18.0 19.8 — 4.3 Less: Accrued SERP - current portion (47.3) (0.3) (0.2) (0.4) (9.7) (0.5) (0.2) (0.5) Accrued Pension, SERP and PBOP $ 135.5 $ 12.9 $ 1.6 $ 6.5 $ 242.5 $ 26.8 $ 2.0 $ 30.2
Schedule of Assumptions Used	The following actuarial assumptions were used in calculating the Pension, SERP and PBOP Plans' year end funded status: Pension and SERP PBOP As of December 31, As of December 31, 2022 2021 2022 2021 Discount Rate 5.1% — 5.2% 2.8% — 3.0% 5.2% 2.91% — 2.92% Compensation/Progression Rate 3.5% — 4.0% 3.5% — 4.0% N/A The following actuarial assumptions were used to calculate Pension, SERP and PBOP expense amounts: Pension and SERP PBOP For the Years Ended December 31, For the Years Ended December 31, 2022 2021 2020 2022 2021 2020 Discount Rate 2.2% — 3.2% 1.5% — 3.0% 2.6% — 3.5% 2.3% — 3.3% 1.8% — 3.1% 2.7% — 3.6% Expected Long-Term Rate of Return 8.25% 8.25% 8.25% 8.25% 8.25% 8.25% Compensation/Progression Rate 3.5% — 4.0% 3.5% — 4.0% 3.5% — 4.0% N/A N/A N/A
Schedule of Net Benefit Costs	The components of net periodic benefit plan expense/(income) for the Pension, SERP and PBOP Plans, prior to amounts capitalized as Property, Plant and Equipment or deferred as regulatory assets/(liabilities) for future recovery or refund, are shown below. The service cost component of net periodic benefit plan expense/(income), less the capitalized portion, is included in Operations and Maintenance expense on the statements of income. The remaining components of net periodic benefit plan expense/(income), less the deferred portion, are included in Other Income, Net on the statements of income. Pension, SERP and PBOP expense reflected in the statements of cash flows for CL&P, NSTAR Electric and PSNH does not include intercompany allocations of net periodic benefit plan expense/(income), as these amounts are cash settled on a short-term basis. Pension and SERP PBOP For the Year Ended December 31, 2022 For the Year Ended December 31, 2022 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 70.1 $ 18.7 $ 13.8 $ 6.9 $ 11.6 $ 2.0 $ 2.0 $ 1.1 Interest Cost 154.5 31.3 32.8 16.9 20.2 3.7 5.3 2.2 Expected Return on Plan Assets (523.6) (106.3) (128.4) (56.1) (89.9) (11.4) (42.4) (6.7) Actuarial Loss 116.0 16.2 32.8 7.9 — — — — Prior Service Cost/(Credit) 1.4 — 0.3 — (21.7) 1.1 (17.0) 0.4 Total Net Periodic Benefit Plan Income $ (181.6) $ (40.1) $ (48.7) $ (24.4) $ (79.8) $ (4.6) $ (52.1) $ (3.0) Intercompany Income Allocations N/A $ (16.0) $ (12.4) $ (3.6) N/A $ (3.7) $ (3.6) $ (1.2) Pension and SERP PBOP For the Year Ended December 31, 2021 For the Year Ended December 31, 2021 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 85.8 $ 23.0 $ 15.8 $ 8.9 $ 13.5 $ 2.3 $ 2.4 $ 1.2 Interest Cost 130.0 27.3 26.8 14.5 17.4 3.2 4.4 1.8 Expected Return on Plan Assets (437.5) (86.8) (108.1) (47.5) (79.1) (10.3) (36.9) (6.1) Actuarial Loss 243.9 45.5 61.6 20.7 8.9 1.8 2.4 0.7 Prior Service Cost/(Credit) 1.4 — 0.3 — (21.2) 1.1 (17.0) 0.4 Total Net Periodic Benefit Plan Expense/(Income) $ 23.6 $ 9.0 $ (3.6) $ (3.4) $ (60.5) $ (1.9) $ (44.7) $ (2.0) Intercompany Expense/(Income) Allocations N/A $ 8.0 $ 8.8 $ 2.7 N/A $ (1.6) $ (1.9) $ (0.6) Pension and SERP PBOP For the Year Ended December 31, 2020 For the Year Ended December 31, 2020 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 76.2 $ 21.8 $ 15.4 $ 8.2 $ 10.2 $ 1.7 $ 2.1 $ 0.9 Interest Cost 177.8 37.3 38.6 19.4 24.6 4.4 6.6 2.8 Expected Return on Plan Assets (400.3) (79.2) (103.0) (44.7) (73.6) (9.9) (34.0) (5.7) Actuarial Loss 202.0 39.2 55.2 15.6 8.4 1.1 2.5 0.8 Prior Service Cost/(Credit) 1.2 — 0.3 — (21.2) 1.1 (17.0) 0.4 Total Net Periodic Benefit Plan Expense/(Income) $ 56.9 $ 19.1 $ 6.5 $ (1.5) $ (51.6) $ (1.6) $ (39.8) $ (0.8) Intercompany Expense/(Income) Allocations N/A $ 9.1 $ 8.9 $ 2.9 N/A $ (1.1) $ (1.4) $ (0.5)
Schedule of Amounts Recognized in Regulatory Assets and OCI	The following is a summary of the changes in plan assets and benefit obligations recognized in Regulatory Assets and Other Comprehensive Income (OCI) as well as amounts in Regulatory Assets and OCI that were reclassified as net periodic benefit expense during the years presented: Pension and SERP PBOP Regulatory Assets OCI Regulatory Assets OCI For the Years Ended December 31, For the Years Ended December 31, (Millions of Dollars) 2022 2021 2022 2021 2022 2021 2022 2021 Actuarial (Gains)/Losses Arising During the Year $ (431.6) $ (961.7) $ 4.6 $ (28.4) $ 36.8 $ (181.5) $ (0.8) $ (4.0) Actuarial Losses Reclassified as Net Periodic Benefit Expense (107.0) (231.2) (9.0) (12.7) — (8.5) — (0.4) Prior Service (Cost)/Credit Reclassified as Net Periodic (1.2) (1.3) (0.2) (0.1) 21.8 21.1 (0.1) 0.1 The following is a summary of the remaining Regulatory Assets and Accumulated Other Comprehensive Income amounts that have not been recognized as components of net periodic benefit expense as of December 31, 2022 and 2021: Regulatory Assets as of December 31, AOCI as of December 31, (Millions of Dollars) 2022 2021 2022 2021 Pension and SERP Actuarial Loss $ 888.7 $ 1,427.3 $ 61.9 $ 66.3 Prior Service Cost 4.1 5.3 0.4 0.6 PBOP Actuarial Loss $ 81.8 $ 45.0 $ 2.7 $ 3.5 Prior Service (Credit)/Cost (108.3) (130.1) 0.9 1.0
Schedule of Expected Benefit Payments	The following benefit payments, which reflect expected future service, are expected to be paid by the Pension, SERP and PBOP Plans: (Millions of Dollars) 2023 2024 2025 2026 2027 2028 - 2032 Pension and SERP $ 401.4 $ 374.4 $ 380.1 $ 383.0 $ 384.1 $ 1,901.7 PBOP 57.9 57.3 56.6 55.5 54.4 253.7
Schedule of Allocation of Plan Assets	These long-term rates of return are based on the assumed rates of return for the target asset allocations as follows: As of December 31, 2022 2021 Eversource Pension Plan and PBOP Plan Eversource Pension Plan and PBOP Plan Target Asset Allocation Assumed Rate of Return Target Asset Allocation Assumed Rate of Return Equity Securities: United States 15.0 % 8.5 % 15.0 % 8.5 % Global 10.0 % 8.75 % 10.0 % 8.75 % Non-United States 8.0 % 8.5 % 8.0 % 8.5 % Emerging Markets 4.0 % 10.0 % 4.0 % 10.0 % Debt Securities: Fixed Income 13.0 % 4.0 % 13.0 % 4.0 % Public High Yield Fixed Income 4.0 % 6.5 % 4.0 % 6.5 % Private Debt 13.0 % 9.0 % 13.0 % 9.0 % Private Equity 18.0 % 12.0 % 18.0 % 12.0 % Real Assets 15.0 % 7.5 % 15.0 % 7.5 % The following table presents, by asset category, the Pension and PBOP Plan assets recorded at fair value on a recurring basis by the level in which they are classified within the fair value hierarchy: Pension Plan Fair Value Measurements as of December 31, (Millions of Dollars) 2022 2021 Asset Category: Level 1 Level 2 Uncategorized Total Level 1 Level 2 Uncategorized Total Equity Securities $ 407.7 $ — $ 1,102.2 $ 1,509.9 $ 722.5 $ — $ 1,385.2 $ 2,107.7 Fixed Income (1) 277.1 78.5 1,598.8 1,954.4 139.6 233.8 1,689.1 2,062.5 Private Equity — — 1,684.9 1,684.9 — — 1,702.7 1,702.7 Real Assets 181.8 — 731.0 912.8 218.3 — 702.8 921.1 Total $ 866.6 $ 78.5 $ 5,116.9 $ 6,062.0 $ 1,080.4 $ 233.8 $ 5,479.8 $ 6,794.0 Less: 401(h) PBOP Assets (2) (255.6) (298.5) Total Pension Assets $ 5,806.4 $ 6,495.5 PBOP Plan Fair Value Measurements as of December 31, (Millions of Dollars) 2022 2021 Asset Category: Level 1 Level 2 Uncategorized Total Level 1 Level 2 Uncategorized Total Equity Securities $ 153.2 $ — $ 183.5 $ 336.7 $ 191.4 $ — $ 248.3 $ 439.7 Fixed Income 18.2 40.2 141.1 199.5 49.7 45.2 125.5 220.4 Private Equity — — 70.9 70.9 — — 58.7 58.7 Real Assets 71.2 — 36.2 107.4 90.0 — 31.0 121.0 Total $ 242.6 $ 40.2 $ 431.7 $ 714.5 $ 331.1 $ 45.2 $ 463.5 $ 839.8 Add: 401(h) PBOP Assets (2) 255.6 298.5 Total PBOP Assets $ 970.1 $ 1,138.3 (1) Fixed Income investments classified as Level 1 as of December 31, 2022 include pending redemption settlements of $138 million. (2) The assets of the Pension Plan include a 401(h) account that has been allocated to provide health and welfare postretirement benefits under the PBOP Plan.
Schedule of Defined Contribution Plans	The total Eversource 401k Plan employer matching contributions, including the K-Vantage contributions, were as follows: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2022 $ 59.9 $ 7.7 $ 12.8 $ 4.8 2021 55.5 7.0 12.2 4.3 2020 49.4 6.6 11.8 4.1
Summary of Share Transactions	A summary of RSU transactions is as follows: RSUs Weighted Average Outstanding as of December 31, 2021 594,623 $ 65.70 Granted 218,005 $ 85.96 Shares Issued (174,633) $ 79.89 Forfeited (8,261) $ 85.87 Outstanding as of December 31, 2022 629,734 $ 68.52 Performance Shares Weighted Average Outstanding as of December 31, 2021 464,507 $ 80.54 Granted 337,406 $ 83.34 Shares Issued (248,981) $ 68.96 Forfeited (5,642) $ 85.28 Outstanding as of December 31, 2022 547,290 $ 87.49
Schedule of Compensation Expense and Income Tax Benefit	The total compensation expense and associated future income tax benefits recognized by Eversource, CL&P, NSTAR Electric and PSNH for share-based compensation awards were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Compensation Expense $ 33.4 $ 28.2 $ 33.9 Future Income Tax Benefit 8.7 7.3 8.9 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Compensation Expense $ 10.0 $ 10.7 $ 3.6 $ 8.8 $ 9.0 $ 3.0 $ 10.9 $ 11.3 $ 3.6 Future Income Tax Benefit 2.6 2.8 0.9 2.3 2.3 0.8 2.9 3.0 1.0
Schedule of Other Retirement Benefits	The liability and expense amounts are as follows: Eversource (Millions of Dollars) As of and For the Years Ended December 31, 2022 2021 2020 Actuarially-Determined Liability $ 43.4 $ 42.8 $ 45.7 Other Retirement Benefits Expense (1) 10.9 2.2 3.3 As of and For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH Actuarially-Determined Liability $ 0.2 $ 0.1 $ 1.3 $ 0.2 $ 0.1 $ 1.5 $ 0.2 $ 0.1 $ 1.7 Other Retirement Benefits Expense (1) 4.0 3.7 1.3 0.7 0.7 0.3 1.2 1.1 0.5 (1) Other Retirement Benefits Expense in 2022 includes a one-time special retirement benefit payable of $9.2 million.

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Components of Income Tax Expense	The components of income tax expense are as follows: Eversource (Millions of Dollars) For the Years Ended December 31, 2022 2021 2020 Current Income Taxes: Federal $ 95.8 $ 21.5 $ 73.6 State 13.6 (21.6) 19.1 Total Current 109.4 (0.1) 92.7 Deferred Income Taxes, Net: Federal 198.8 199.7 173.5 State 148.0 147.4 83.7 Total Deferred 346.8 347.1 257.2 Investment Tax Credits, Net (2.6) (2.8) (3.7) Income Tax Expense $ 453.6 $ 344.2 $ 346.2 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH Current Income Taxes: Federal $ 106.2 $ 55.0 $ 29.6 $ 15.0 $ 52.3 $ 43.1 $ 12.0 $ 53.9 $ 20.6 State 20.1 8.7 5.9 (7.0) 6.2 10.8 (6.1) 6.9 3.8 Total Current 126.3 63.7 35.5 8.0 58.5 53.9 5.9 60.8 24.4 Deferred Income Taxes, Net: Federal 17.2 35.6 5.9 76.3 16.3 (14.9) 101.1 33.8 (1.3) State 28.2 42.4 9.9 47.6 41.2 0.4 43.4 38.8 8.6 Total Deferred 45.4 78.0 15.8 123.9 57.5 (14.5) 144.5 72.6 7.3 Investment Tax Credits, Net (0.5) (1.7) — (0.6) (1.7) — (0.7) (2.6) — Income Tax Expense $ 171.2 $ 140.0 $ 51.3 $ 131.3 $ 114.3 $ 39.4 $ 149.7 $ 130.8 $ 31.7
Summary of Reconciliation Between Income Tax Expense and Expected Tax	A reconciliation between income tax expense and the expected tax expense at the statutory rate is as follows: Eversource (Millions of Dollars, except percentages) For the Years Ended December 31, 2022 2021 2020 Income Before Income Tax Expense $ 1,866.0 $ 1,572.3 $ 1,558.9 Statutory Federal Income Tax Expense at 21% 391.9 330.2 327.4 Tax Effect of Differences: Depreciation (17.1) (18.1) (11.1) Investment Tax Credit Amortization (2.6) (2.8) (3.7) State Income Taxes, Net of Federal Impact 75.9 54.4 44.9 Dividends on ESOP (5.1) (5.1) (5.1) Tax Asset Valuation Allowance/Reserve Adjustments 51.6 44.6 33.4 Excess Stock Benefit (2.1) (4.0) (6.6) EDIT Amortization (49.1) (69.1) (48.7) Other, Net 10.2 14.1 15.7 Income Tax Expense $ 453.6 $ 344.2 $ 346.2 Effective Tax Rate 24.3 % 21.9 % 22.2 % For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars, except percentages) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Income Before Income Tax Expense $ 704.1 $ 632.4 $ 222.9 $ 533.0 $ 590.9 $ 189.8 $ 607.6 $ 575.8 $ 179.0 Statutory Federal Income Tax Expense at 21% 147.9 132.8 46.8 111.9 124.1 39.9 127.6 120.9 37.6 Tax Effect of Differences: Depreciation (3.7) (4.2) 0.9 (6.4) (3.4) (0.2) 0.4 (3.7) (1.4) Investment Tax Credit Amortization (0.5) (1.7) — (0.6) (1.7) — (0.7) (2.6) — State Income Taxes, Net of Federal Impact (6.6) 40.3 12.5 (4.6) 37.5 8.9 (1.2) 36.0 9.8 Tax Asset Valuation 44.7 — — 36.7 — — 30.7 — — Excess Stock Benefit (0.7) (0.8) (0.3) (1.5) (1.4) (0.5) (2.3) (2.3) (0.8) EDIT Amortization (9.2) (29.2) (7.7) (9.8) (43.2) (10.5) (9.0) (20.4) (15.4) Other, Net (0.7) 2.8 (0.9) 5.6 2.4 1.8 4.2 2.9 1.9 Income Tax Expense $ 171.2 $ 140.0 $ 51.3 $ 131.3 $ 114.3 $ 39.4 $ 149.7 $ 130.8 $ 31.7 Effective Tax Rate 24.3 % 22.1 % 23.0 % 24.6 % 19.3 % 20.8 % 24.6 % 22.7 % 17.7 %
Schedule of Accumulated Deferred Income Tax Obligations	The tax effects of temporary differences that give rise to the net accumulated deferred income tax obligations are as follows: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Deferred Tax Assets: Employee Benefits $ 228.9 $ 25.3 $ 57.4 $ 11.6 $ 270.8 $ 23.9 $ 40.3 $ 14.1 Derivative Liabilities 53.8 53.8 — — 76.8 76.8 — — Regulatory Deferrals - Liabilities 529.5 146.6 285.7 42.1 390.7 90.9 215.4 24.3 Allowance for Uncollectible Accounts 125.5 60.5 20.7 7.9 104.1 48.8 21.5 6.2 Tax Effect - Tax Regulatory Liabilities 762.9 324.6 241.8 97.8 783.4 328.2 254.3 100.9 Net Operating Loss Carryforwards 16.7 — — — 7.5 — — — Purchase Accounting Adjustment 62.0 — — — 67.2 — — — Other 176.6 109.5 20.5 21.3 196.6 103.9 21.7 22.9 Total Deferred Tax Assets 1,955.9 720.3 626.1 180.7 1,897.1 672.5 553.2 168.4 Less: Valuation Allowance 82.8 63.3 — — 61.5 44.5 — — Net Deferred Tax Assets $ 1,873.1 $ 657.0 $ 626.1 $ 180.7 $ 1,835.6 $ 628.0 $ 553.2 $ 168.4 Deferred Tax Liabilities: Accelerated Depreciation and Other $ 4,793.7 $ 1,602.0 $ 1,643.7 $ 523.8 $ 4,426.0 $ 1,509.5 $ 1,553.7 $ 482.9 Property Tax Accruals 95.3 40.7 41.3 6.7 88.1 40.5 33.7 6.3 Regulatory Amounts: Regulatory Deferrals - Assets 1,251.9 406.4 407.9 165.2 1,260.3 438.3 337.6 198.4 Tax Effect - Tax Regulatory Assets 271.7 185.6 10.7 7.9 257.8 181.4 10.9 8.3 Goodwill-related Regulatory Asset - 1999 Merger 76.8 — 65.9 — 81.4 — 69.9 — Employee Benefits 305.5 45.0 140.8 18.7 174.7 3.5 107.1 0.7 Derivative Assets 10.5 10.5 — — 14.9 14.9 — — Other 135.6 6.8 16.7 21.2 129.5 2.0 19.8 9.8 Total Deferred Tax Liabilities $ 6,941.0 $ 2,297.0 $ 2,327.0 $ 743.5 $ 6,432.7 $ 2,190.1 $ 2,132.7 $ 706.4
Summary of Tax Credits and Loss Carryforwards	The following table provides the amounts and expiration dates of state tax credit and loss carryforwards and federal tax credit and net operating loss carryforwards: As of December 31, 2022 2021 (Millions of Dollars) Eversource CL&P NSTAR PSNH Expiration Range Eversource CL&P NSTAR PSNH Expiration Range State Net Operating Loss $ 288.1 $ — $ — $ — 2022 - 2041 $ 138.3 $ — $ — $ — 2021 - 2040 State Tax Credit 204.5 137.7 — — 2022 - 2027 197.7 137.0 — — 2021 - 2026 State Charitable Contribution 20.1 — — — 2022 - 2026 23.7 — — — 2021 - 2025
Summary of Income Tax Contingencies	A reconciliation of the activity in unrecognized tax benefits, all of which would impact the effective tax rate if recognized, is as follows: (Millions of Dollars) Eversource CL&P Balance as of January 1, 2020 $ 55.0 $ 23.1 Gross Increases - Current Year 11.9 4.6 Gross Increases - Prior Year 1.4 0.7 Lapse of Statute of Limitations (6.5) (2.6) Balance as of December 31, 2020 61.8 25.8 Gross Increases - Current Year 11.3 3.8 Gross Decreases - Prior Year (0.3) (0.6) Lapse of Statute of Limitations (7.0) (2.8) Balance as of December 31, 2021 65.8 26.2 Gross Increases - Current Year 11.5 3.5 Gross Decreases - Prior Year (2.4) (0.9) Lapse of Statute of Limitations (7.8) (3.3) Balance as of December 31, 2022 $ 67.1 $ 25.5
Summary of Income Tax Examinations	The following table summarizes Eversource, CL&P, NSTAR Electric, and PSNH's tax years that remain subject to examination by major tax jurisdictions as of December 31, 2022: Description Tax Years Federal 2022 Connecticut 2019 - 2022 Massachusetts 2019 - 2022 New Hampshire 2019 - 2022

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Schedule of Environmental Loss Contingencies by Site	A reconciliation of the activity in the environmental reserves is as follows: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Balance as of January 1, 2021 $ 102.4 $ 12.3 $ 4.7 $ 7.1 Additions 23.4 4.4 — — Payments/Reductions (10.4) (2.8) (1.4) (0.8) Balance as of December 31, 2021 115.4 13.9 3.3 6.3 Additions 12.6 0.9 0.4 0.5 Payments/Reductions (5.4) (0.9) (0.3) (0.7) Balance as of December 31, 2022 $ 122.6 $ 13.9 $ 3.4 $ 6.1 The number of environmental sites for which remediation or long-term monitoring, preliminary site work or site assessment is being performed are as follows: Eversource CL&P NSTAR Electric PSNH 2022 59 13 10 8 2021 61 14 11 9
Schedule of Estimated Future Annual Costs of Long term Contractual Agreement	The estimated future annual costs of significant executed, non-cancelable, long-term contractual arrangements in effect as of December 31, 2022 are as follows: Eversource (Millions of Dollars) 2023 2024 2025 2026 2027 Thereafter Total Renewable Energy Purchase Contracts $ 751.8 $ 952.6 $ 954.8 $ 983.0 $ 998.5 $ 8,141.1 $ 12,781.8 Natural Gas Procurement 447.1 419.4 340.9 298.5 269.4 1,450.6 3,225.9 Purchased Power and Capacity 87.6 86.8 75.2 2.9 2.7 7.2 262.4 Peaker CfDs 20.3 21.1 17.9 16.0 11.4 64.4 151.1 Transmission Support Commitments 17.8 20.7 22.6 22.6 22.6 22.6 128.9 Total $ 1,324.6 $ 1,500.6 $ 1,411.4 $ 1,323.0 $ 1,304.6 $ 9,685.9 $ 16,550.1 CL&P (Millions of Dollars) 2023 2024 2025 2026 2027 Thereafter Total Renewable Energy Purchase Contracts $ 594.8 $ 609.1 $ 610.2 $ 607.6 $ 609.0 $ 2,253.1 $ 5,283.8 Purchased Power and Capacity 83.5 83.9 72.4 0.1 — — 239.9 Peaker CfDs 20.3 21.1 17.9 16.0 11.4 64.4 151.1 Transmission Support Commitments 7.0 8.2 8.9 8.9 8.9 8.9 50.8 Total $ 705.6 $ 722.3 $ 709.4 $ 632.6 $ 629.3 $ 2,326.4 $ 5,725.6 NSTAR Electric (Millions of Dollars) 2023 2024 2025 2026 2027 Thereafter Total Renewable Energy Purchase Contracts $ 79.2 $ 270.0 $ 316.5 $ 322.9 $ 328.6 $ 5,519.8 $ 6,837.0 Purchased Power and Capacity 2.9 2.9 2.8 2.8 2.7 7.2 21.3 Transmission Support Commitments 7.0 8.1 8.9 8.9 8.9 8.9 50.7 Total $ 89.1 $ 281.0 $ 328.2 $ 334.6 $ 340.2 $ 5,535.9 $ 6,909.0 PSNH (Millions of Dollars) 2023 2024 2025 2026 2027 Thereafter Total Renewable Energy Purchase Contracts $ 77.8 $ 73.5 $ 28.1 $ 52.5 $ 60.9 $ 368.2 $ 661.0 Purchased Power and Capacity 1.2 — — — — — 1.2 Transmission Support Commitments 3.8 4.4 4.8 4.8 4.8 4.8 27.4 Total $ 82.8 $ 77.9 $ 32.9 $ 57.3 $ 65.7 $ 373.0 $ 689.6 The total costs incurred under these agreements were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Renewable Energy Purchase Contracts $ 678.1 $ 609.2 $ 584.2 Natural Gas Procurement 1,042.8 712.7 453.4 Purchased Power and Capacity 61.6 56.4 62.7 Peaker CfDs 13.4 24.3 22.7 Transmission Support Commitments 12.7 15.4 22.1 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Renewable Energy Purchase Contracts $ 513.2 $ 90.8 $ 74.1 $ 457.1 $ 84.7 $ 67.4 $ 426.3 $ 88.8 $ 69.1 Purchased Power and Capacity 57.7 3.0 0.9 53.1 3.0 0.3 59.3 3.1 0.3 Peaker CfDs 13.4 — — 24.3 — — 22.7 — — Transmission Support Commitments 5.0 5.0 2.7 6.1 6.0 3.3 8.7 8.7 4.7
Schedule of Guarantor Obligations	The following table summarizes Eversource parent's exposure to guarantees and indemnifications of its subsidiaries and affiliates to external parties, and primarily relates to its offshore wind business: As of December 31, 2022 Company (Obligor) Description Maximum Exposure Expiration Dates North East Offshore LLC Construction-related purchase agreements with third-party contractors (1) $ 717.6 (1) Sunrise Wind LLC Construction-related purchase agreements with third-party contractors (2) 311.5 2025 - 2026 Revolution Wind, LLC Construction-related purchase agreements with third-party contractors (3) 419.1 2024 - 2027 South Fork Wind, LLC Construction-related purchase agreements with third-party contractors (4) 142.1 2023 - 2026 Eversource Investment LLC Funding and indemnification obligations of North East Offshore LLC (5) 77.0 (5) South Fork Wind, LLC Power Purchase Agreement Security (6) 7.1 (6) Sunrise Wind LLC OREC capacity production (7) 2.2 (7) Bay State Wind LLC Real estate purchase 2.5 2023 South Fork Wind, LLC Transmission interconnection 1.2 — Eversource Investment LLC Letters of Credit (8) 4.3 — Various Surety bonds (9) 35.7 2023 Eversource Service Lease payments for real estate 0.5 2024 (1) Eversource parent issued guarantees on behalf of its 50 percent-owned affiliate, North East Offshore LLC (NEO), under which Eversource parent agreed to guarantee 50 percent of NEO’s performance of obligations under certain purchase agreements with third-party contractors, in an aggregate amount not to exceed $1.3 billion with an expiration date in 2025. Eversource parent also issued a separate guarantee to Ørsted on behalf of NEO, under which Eversource parent agreed to guarantee 50 percent of NEO’s payment obligations under certain offshore wind project construction-related agreements with Ørsted in an aggregate amount not to exceed $62.5 million and expiring upon full performance of the guaranteed obligation. Any amounts paid under this guarantee to Ørsted will count toward, but not increase, the maximum amount of the Funding Guarantee described in Note 5, below. (2) Eversource parent issued guarantees on behalf of its 50 percent-owned affiliate, Sunrise Wind LLC, whereby Eversource parent will guarantee Sunrise Wind LLC's performance of certain obligations, in an aggregate amount not to exceed $465.8 million, in connection with construction-related purchase agreements. Eversource parent’s obligations under the guarantees expire upon the earlier of (i) dates ranging from March 2025 and April 2026 and (ii) full performance of the guaranteed obligations. (3) Eversource parent issued guarantees on behalf of its 50 percent-owned affiliate, Revolution Wind, LLC, whereby Eversource parent will guarantee Revolution Wind, LLC's performance of certain obligations, in an aggregate amount not to exceed $546.7 million, in connection with construction-related purchase agreements. Eversource parent’s obligations under the guarantees expire upon the earlier of (i) dates ranging from May 2024 and November 2027 and (ii) full performance of the guaranteed obligations. (4) Eversource parent issued guarantees on behalf of its 50 percent-owned affiliate, South Fork Wind, LLC, whereby Eversource parent will guarantee South Fork Wind, LLC's performance of certain obligations in connection with construction-related purchase agreements. Under these guarantees, Eversource parent will guarantee South Fork Wind, LLC's performance of certain obligations, in a total aggregate amount not to exceed $207.7 million. Eversource parent’s obligations under these guarantees expire upon the earlier of (i) dates ranging from June 2023 and August 2026 and (ii) full performance of the guaranteed obligations. (5) Eversource parent issued a guarantee (Funding Guarantee) on behalf of Eversource Investment LLC (EI), its wholly-owned subsidiary that holds a 50 percent ownership interest in NEO, under which Eversource parent agreed to guarantee certain funding obligations and certain indemnification payments of EI under the operating agreement of NEO, in an amount not to exceed $910 million. The guaranteed obligations include payment of EI's funding obligations during the construction phase of NEO’s underlying offshore wind projects and indemnification obligations associated with third party credit support for its investment in NEO. Eversource parent’s obligations under the Funding Guarantee expire upon the full performance of the guaranteed obligations. (6) Eversource parent issued a guarantee on behalf of its 50 percent-owned affiliate, South Fork Wind, LLC, whereby Eversource parent will guarantee South Fork Wind, LLC's performance of certain obligations, in an amount not to exceed $7.1 million, under a Power Purchase Agreement between the Long Island Power Authority and South Fork Wind, LLC (the Agreement). The guarantee expires upon the later of (i) the end of the Agreement term and (ii) full performance of the guarantee obligations. (7) Eversource parent issued a guarantee on behalf of its 50 percent-owned affiliate, Sunrise Wind LLC, whereby Eversource parent will guarantee Sunrise Wind LLC's performance of certain obligations, in an amount not to exceed $15.4 million, under the Offshore Wind Renewable Energy Certificate Purchase and Sale Agreement (the Agreement). The Agreement was executed by and between the New York State Energy Research and Development Authority (NYSERDA) and Sunrise Wind LLC. The guarantee expires upon the full performance of the guaranteed obligations. Effective January 1, 2023, exposure under the guarantee increased from $2.2 million to $11.0 million. (8) On September 16, 2020, Eversource parent entered into a guarantee on behalf of EI, which holds Eversource's investments in offshore wind-related equity method investments, under which Eversource parent would guarantee EI's obligations under a letter of credit facility with a financial institution that EI may request in an aggregate amount of up to approximately $25 million. In January 2022, Eversource parent issued two letters of credit on behalf of South Fork Wind, LLC related to future decommissioning obligations of certain onshore transmission assets totaling $4.3 million. (9) Surety bond expiration dates reflect termination dates, the majority of which will be renewed or extended. Certain surety bonds contain credit ratings triggers that would require Eversource parent to post collateral in the event that the unsecured debt credit ratings of Eversource parent are downgraded.

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Components of Lease Cost	The components of lease cost, prior to amounts capitalized, are as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2022 2021 2020 Finance Lease Cost: Amortization of Right-of-use-Assets $ 8.3 $ 4.6 $ 2.6 Interest on Lease Liabilities 2.0 3.9 1.4 Total Finance Lease Cost 10.3 8.5 4.0 Operating Lease Cost 11.6 12.2 11.1 Variable Lease Cost 78.1 61.0 57.8 Total Lease Cost $ 100.0 $ 81.7 $ 72.9 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Finance Lease Cost: Amortization of Right-of-use-Assets $ — $ 0.2 $ 0.1 $ 0.5 $ 0.2 $ 0.1 $ 0.7 $ 0.2 $ 0.1 Interest on Lease Liabilities — 0.6 — 0.1 0.6 — 0.3 0.6 — Total Finance Lease Cost — 0.8 0.1 0.6 0.8 0.1 1.0 0.8 0.1 Operating Lease Cost 0.3 2.3 0.1 0.3 2.3 0.1 0.6 2.1 0.1 Variable Lease Cost 25.6 — 52.5 16.2 — 44.8 12.2 — 45.6 Total Lease Cost $ 25.9 $ 3.1 $ 52.7 $ 17.1 $ 3.1 $ 45.0 $ 13.8 $ 2.9 $ 45.8
Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases is as follows: As of December 31, 2022 As of December 31, 2021 (Millions of Dollars) Balance Sheet Classification Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Operating Leases: Right-of-use-Assets, Net Other Long-Term Assets $ 56.9 $ 2.2 $ 22.5 $ — $ 47.2 $ 0.1 $ 24.3 $ 0.3 Operating Lease Liabilities Current Portion Other Current Liabilities $ 9.0 $ 0.6 $ 1.2 $ — $ 10.0 $ 0.1 $ 1.1 $ — Long-Term Other Long-Term Liabilities 47.9 1.6 21.3 — 37.2 — 23.2 0.3 Total Operating Lease Liabilities $ 56.9 $ 2.2 $ 22.5 $ — $ 47.2 $ 0.1 $ 24.3 $ 0.3 Finance Leases: Right-of-use-Assets, Net Property, Plant and Equipment, Net $ 54.5 $ — $ 3.2 $ — $ 58.0 $ — $ 3.3 $ 0.7 Finance Lease Liabilities Current Portion Other Current Liabilities $ 3.8 $ — $ — $ — $ 3.9 $ — $ — $ 0.1 Long-Term Other Long-Term Liabilities 54.2 — 4.9 — 55.4 — 4.9 0.6 Total Finance Lease Liabilities $ 58.0 $ — $ 4.9 $ — $ 59.3 $ — $ 4.9 $ 0.7
Other Information Related to Leases	Other information related to leases is as follows: As of December 31, 2022 2021 Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Weighted-Average Remaining Lease Term (Years): Operating Leases 11 4 17 — 13 7 18 7 Finance Leases 15 — 19 — 16 — 20 7 Weighted-Average Discount Rate (Percentage): Operating Leases 3.2 % 3.8 % 4.0 % — % 4.1 % 3.0 % 4.0 % 3.7 % Finance Leases 2.7 % — % 2.9 % — % 2.7 % — % 2.9 % 3.5 % (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2022 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 11.3 $ 0.3 $ 2.1 $ 0.1 Operating Cash Flows from Finance Leases 2.0 — 0.6 — Financing Cash Flows from Finance Leases 3.9 — — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 18.9 2.4 — — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 3.5 — — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2021 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 12.1 $ 0.3 $ 2.1 $ 0.1 Operating Cash Flows from Finance Leases 3.4 0.1 0.6 — Financing Cash Flows from Finance Leases 4.1 1.4 — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 2.1 — 1.9 — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 2.3 — — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2020 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 10.9 $ 0.6 $ 1.8 $ 0.1 Operating Cash Flows from Finance Leases 1.7 0.3 0.6 — Financing Cash Flows from Finance Leases 2.8 1.6 — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 0.6 0.1 0.2 — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 0.7 — 0.3 —
Future Minimum Lease Payments under Long-Term Finance Leases	Future minimum lease payments, excluding variable costs, under long-term leases, as of December 31, 2022 are as follows: Operating Leases Finance Leases (Millions of Dollars) Eversource CL&P NSTAR Electric Eversource NSTAR Electric Year Ending December 31, 2023 $ 10.3 $ 0.7 $ 2.1 $ 5.9 $ 0.6 2024 9.3 0.7 2.1 5.9 0.6 2025 6.4 0.7 1.7 5.9 0.6 2026 5.5 0.3 1.7 5.4 0.7 2027 5.2 — 1.7 5.4 0.7 Thereafter 31.2 — 23.6 50.9 11.8 Future lease payments 67.9 2.4 32.9 79.4 15.0 Less amount representing interest 11.0 0.2 10.4 21.4 10.1 Present value of future minimum lease payments $ 56.9 $ 2.2 $ 22.5 $ 58.0 $ 4.9
Future Minimum Lease Payments under Long-Term Operating Leases	Future minimum lease payments, excluding variable costs, under long-term leases, as of December 31, 2022 are as follows: Operating Leases Finance Leases (Millions of Dollars) Eversource CL&P NSTAR Electric Eversource NSTAR Electric Year Ending December 31, 2023 $ 10.3 $ 0.7 $ 2.1 $ 5.9 $ 0.6 2024 9.3 0.7 2.1 5.9 0.6 2025 6.4 0.7 1.7 5.9 0.6 2026 5.5 0.3 1.7 5.4 0.7 2027 5.2 — 1.7 5.4 0.7 Thereafter 31.2 — 23.6 50.9 11.8 Future lease payments 67.9 2.4 32.9 79.4 15.0 Less amount representing interest 11.0 0.2 10.4 21.4 10.1 Present value of future minimum lease payments $ 56.9 $ 2.2 $ 22.5 $ 58.0 $ 4.9

FAIR VALUE OF FINANCIAL INSTR_2

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Carrying Amounts and Estimated Fair Values of Financial Instruments	The fair values provided in the table below are classified as Level 2 within the fair value hierarchy. Carrying amounts and estimated fair values are as follows: Eversource CL&P NSTAR Electric PSNH (Millions of Dollars) Carrying Amount Fair Value Carrying Fair Carrying Fair Carrying Fair As of December 31, 2022: Preferred Stock Not Subject to Mandatory Redemption $ 155.6 $ 136.7 $ 116.2 $ 99.2 $ 43.0 $ 37.5 $ — $ — Long-Term Debt 21,044.1 18,891.3 4,216.5 3,828.3 4,425.1 4,091.8 1,164.6 970.5 Rate Reduction Bonds 453.7 424.7 — — — — 453.7 424.7 As of December 31, 2021: Preferred Stock Not Subject to Mandatory Redemption $ 155.6 $ 166.3 $ 116.2 $ 122.3 $ 43.0 $ 44.0 $ — $ — Long-Term Debt 18,216.7 19,636.3 4,215.4 4,848.9 3,985.4 4,453.5 1,163.8 1,220.6 Rate Reduction Bonds 496.9 543.3 — — — — 496.9 543.3

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) (Tables)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Changes in Accumulated Other Comprehensive Income/(Loss) by Component, Net of Tax	The changes in accumulated other comprehensive income/(loss) by component, net of tax, are as follows: For the Year Ended December 31, 2022 For the Year Ended December 31, 2021 Eversource (Millions of Dollars) Qualified Unrealized Defined Total Qualified Unrealized Defined Total Balance as of January 1st $ (0.4) $ 0.4 $ (42.3) $ (42.3) $ (1.4) $ 1.1 $ (76.1) $ (76.4) OCI Before Reclassifications — (1.6) (2.5) (4.1) — (0.7) 24.1 23.4 Amounts Reclassified from AOCI — — 7.0 7.0 1.0 — 9.7 10.7 Net OCI — (1.6) 4.5 2.9 1.0 (0.7) 33.8 34.1 Balance as of December 31st $ (0.4) $ (1.2) $ (37.8) $ (39.4) $ (0.4) $ 0.4 $ (42.3) $ (42.3)
Schedule of Amounts Reclassified from AOCI by Component	The following table sets forth the amounts reclassified from AOCI by component and the impacted line item on the statements of income: Amounts Reclassified from AOCI Eversource (Millions of Dollars) For the Years Ended December 31, Statements of Income 2022 2021 2020 Qualified Cash Flow Hedging Instruments $ — $ (1.7) $ (2.5) Interest Expense Tax Effect — 0.7 0.9 Income Tax Expense Qualified Cash Flow Hedging Instruments, Net of Tax $ — $ (1.0) $ (1.6) Defined Benefit Plan Costs: Amortization of Actuarial Losses $ (9.0) $ (13.1) $ (8.1) Other Income, Net (1) Amortization of Prior Service Cost (0.3) — (0.3) Other Income, Net (1) Total Defined Benefit Plan Costs (9.3) (13.1) (8.4) Tax Effect 2.3 3.4 2.1 Income Tax Expense Defined Benefit Plan Costs, Net of Tax $ (7.0) $ (9.7) $ (6.3) Total Amounts Reclassified from AOCI, Net of Tax $ (7.0) $ (10.7) $ (7.9) (1) These amounts are included in the computation of net periodic Pension, SERP and PBOP costs. See Note 1K, "Summary of Significant Accounting Policies – Other Income, Net" and Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," for further information.

COMMON SHARES (Tables)

COMMON SHARES (Tables)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Common Shares Authorized and Issued	The following table sets forth the Eversource parent common shares and the shares of common stock of CL&P, NSTAR Electric and PSNH that were authorized and issued, as well as the respective per share par values: Shares Par Value Authorized as of December 31, 2022 and 2021 Issued as of December 31, 2022 2021 Eversource $ 5 380,000,000 359,984,073 357,818,402 CL&P $ 10 24,500,000 6,035,205 6,035,205 NSTAR Electric $ 1 100,000,000 200 200 PSNH $ 1 100,000,000 301 301 Details of preferred stock not subject to mandatory redemption are as follows (in millions, except in redemption price and shares): Redemption Price Shares Outstanding as of December 31, As of December 31, Series 2022 2021 2022 2021 CL&P $1.90 Series of 1947 $ 52.50 163,912 163,912 $ 8.2 $ 8.2 $2.00 Series of 1947 $ 54.00 336,088 336,088 16.8 16.8 $2.04 Series of 1949 $ 52.00 100,000 100,000 5.0 5.0 $2.20 Series of 1949 $ 52.50 200,000 200,000 10.0 10.0 3.90% Series of 1949 $ 50.50 160,000 160,000 8.0 8.0 $2.06 Series E of 1954 $ 51.00 200,000 200,000 10.0 10.0 $2.09 Series F of 1955 $ 51.00 100,000 100,000 5.0 5.0 4.50% Series of 1956 $ 50.75 104,000 104,000 5.2 5.2 4.96% Series of 1958 $ 50.50 100,000 100,000 5.0 5.0 4.50% Series of 1963 $ 50.50 160,000 160,000 8.0 8.0 5.28% Series of 1967 $ 51.43 200,000 200,000 10.0 10.0 $3.24 Series G of 1968 $ 51.84 300,000 300,000 15.0 15.0 6.56% Series of 1968 $ 51.44 200,000 200,000 10.0 10.0 Total CL&P 2,324,000 2,324,000 $ 116.2 $ 116.2 NSTAR Electric 4.25% Series of 1956 $ 103.625 180,000 180,000 $ 18.0 $ 18.0 4.78% Series of 1958 $ 102.80 250,000 250,000 25.0 25.0 Total NSTAR Electric 430,000 430,000 $ 43.0 $ 43.0 Fair Value Adjustment due to Merger with NSTAR (3.6) (3.6) Other 6.00% Series of 1958 $ 100.00 23 23 $ — $ — Total Eversource - Noncontrolling Interest - Preferred Stock of Subsidiaries $ 155.6 $ 155.6

PREFERRED STOCK NOT SUBJECT T_2

PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION (Tables)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Schedule of Preferred Stock Not Subject to Mandatory Redemption	The following table sets forth the Eversource parent common shares and the shares of common stock of CL&P, NSTAR Electric and PSNH that were authorized and issued, as well as the respective per share par values: Shares Par Value Authorized as of December 31, 2022 and 2021 Issued as of December 31, 2022 2021 Eversource $ 5 380,000,000 359,984,073 357,818,402 CL&P $ 10 24,500,000 6,035,205 6,035,205 NSTAR Electric $ 1 100,000,000 200 200 PSNH $ 1 100,000,000 301 301 Details of preferred stock not subject to mandatory redemption are as follows (in millions, except in redemption price and shares): Redemption Price Shares Outstanding as of December 31, As of December 31, Series 2022 2021 2022 2021 CL&P $1.90 Series of 1947 $ 52.50 163,912 163,912 $ 8.2 $ 8.2 $2.00 Series of 1947 $ 54.00 336,088 336,088 16.8 16.8 $2.04 Series of 1949 $ 52.00 100,000 100,000 5.0 5.0 $2.20 Series of 1949 $ 52.50 200,000 200,000 10.0 10.0 3.90% Series of 1949 $ 50.50 160,000 160,000 8.0 8.0 $2.06 Series E of 1954 $ 51.00 200,000 200,000 10.0 10.0 $2.09 Series F of 1955 $ 51.00 100,000 100,000 5.0 5.0 4.50% Series of 1956 $ 50.75 104,000 104,000 5.2 5.2 4.96% Series of 1958 $ 50.50 100,000 100,000 5.0 5.0 4.50% Series of 1963 $ 50.50 160,000 160,000 8.0 8.0 5.28% Series of 1967 $ 51.43 200,000 200,000 10.0 10.0 $3.24 Series G of 1968 $ 51.84 300,000 300,000 15.0 15.0 6.56% Series of 1968 $ 51.44 200,000 200,000 10.0 10.0 Total CL&P 2,324,000 2,324,000 $ 116.2 $ 116.2 NSTAR Electric 4.25% Series of 1956 $ 103.625 180,000 180,000 $ 18.0 $ 18.0 4.78% Series of 1958 $ 102.80 250,000 250,000 25.0 25.0 Total NSTAR Electric 430,000 430,000 $ 43.0 $ 43.0 Fair Value Adjustment due to Merger with NSTAR (3.6) (3.6) Other 6.00% Series of 1958 $ 100.00 23 23 $ — $ — Total Eversource - Noncontrolling Interest - Preferred Stock of Subsidiaries $ 155.6 $ 155.6

REVENUES (Tables)

REVENUES (Tables)	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The following tables present operating revenues disaggregated by revenue source: For the Year Ended December 31, 2022 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 4,796.1 $ 1,204.9 $ — $ 141.7 $ — $ — $ 6,142.7 Commercial 2,903.3 648.5 — 66.5 — (4.1) 3,614.2 Industrial 374.9 199.7 — 4.7 — (20.1) 559.2 Total Retail Tariff Sales Revenues 8,074.3 2,053.1 — 212.9 — (24.2) 10,316.1 Wholesale Transmission Revenues — — 1,700.5 — — (1,264.5) 436.0 Wholesale Market Sales Revenues 1,190.9 140.8 — 3.8 — — 1,335.5 Other Revenues from Contracts with Customers 72.3 5.6 14.1 8.4 1,435.5 (1,425.3) 110.6 Amortization of/(Reserve for) Revenues 72.0 — 0.7 (0.7) — — 72.0 Total Revenues from Contracts with Customers 9,409.5 2,199.5 1,715.3 224.4 1,435.5 (2,714.0) 12,270.2 Alternative Revenue Programs (15.4) 14.8 92.7 (2.5) — (84.3) 5.3 Other Revenues 11.2 1.3 0.7 0.6 — — 13.8 Total Operating Revenues $ 9,405.3 $ 2,215.6 $ 1,808.7 $ 222.5 $ 1,435.5 $ (2,798.3) $ 12,289.3 For the Year Ended December 31, 2021 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 3,989.8 $ 1,000.3 $ — $ 133.5 $ — $ — $ 5,123.6 Commercial 2,486.1 497.6 — 62.8 — (5.1) 3,041.4 Industrial 345.3 167.2 — 4.3 — (17.1) 499.7 Total Retail Tariff Sales Revenues 6,821.2 1,665.1 — 200.6 — (22.2) 8,664.7 Wholesale Transmission Revenues — — 1,751.3 — 86.6 (1,384.7) 453.2 Wholesale Market Sales Revenues 575.8 82.1 — 3.9 — — 661.8 Other Revenues from Contracts with Customers 78.1 5.1 13.6 7.5 1,267.4 (1,257.7) 114.0 Reserve for Revenues Subject to Refund (71.1) — (5.0) (2.6) — — (78.7) Total Revenues from Contracts with Customers 7,404.0 1,752.3 1,759.9 209.4 1,354.0 (2,664.6) 9,815.0 Alternative Revenue Programs 14.7 37.0 (126.1) 1.5 — 114.6 41.7 Other Revenues 4.9 0.3 0.8 0.4 — — 6.4 Total Operating Revenues $ 7,423.6 $ 1,789.6 $ 1,634.6 $ 211.3 $ 1,354.0 $ (2,550.0) $ 9,863.1 For the Year Ended December 31, 2020 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 3,951.5 $ 644.9 $ — $ 145.1 $ — $ — $ 4,741.5 Commercial 2,353.4 361.9 — 62.4 — (4.8) 2,772.9 Industrial 327.1 107.4 — 4.8 — (13.7) 425.6 Total Retail Tariff Sales Revenues 6,632.0 1,114.2 — 212.3 — (18.5) 7,940.0 Wholesale Transmission Revenues — — 1,557.3 — 74.2 (1,290.6) 340.9 Wholesale Market Sales Revenues 327.3 43.0 — 3.8 — — 374.1 Other Revenues from Contracts with Customers 79.3 5.7 13.3 3.5 1,161.7 (1,152.0) 111.5 Total Revenues from Contracts with Customers 7,038.6 1,162.9 1,570.6 219.6 1,235.9 (2,461.1) 8,766.5 Alternative Revenue Programs 88.1 44.7 (35.2) (4.7) — 37.1 130.0 Other Revenues 5.6 1.1 0.7 0.5 — — 7.9 Total Operating Revenues $ 7,132.3 $ 1,208.7 $ 1,536.1 $ 215.4 $ 1,235.9 $ (2,424.0) $ 8,904.4 For the Years Ended December 31, 2022 2021 2020 (Millions of Dollars) CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH Revenues from Contracts with Customers Retail Tariff Sales Residential $ 2,397.2 $ 1,601.8 $ 797.1 $ 1,994.2 $ 1,375.8 $ 619.8 $ 2,011.1 $ 1,365.8 $ 574.6 Commercial 1,067.9 1,457.4 380.8 890.6 1,265.0 332.2 878.3 1,176.8 299.9 Industrial 146.4 135.8 92.7 131.4 119.1 94.8 137.5 106.4 83.2 Total Retail Tariff Sales Revenues 3,611.5 3,195.0 1,270.6 3,016.2 2,759.9 1,046.8 3,026.9 2,649.0 957.7 Wholesale Transmission Revenues 755.1 670.4 275.0 863.3 616.3 271.7 754.8 576.5 226.0 Wholesale Market Sales Revenues 873.7 215.0 102.2 408.8 109.2 57.8 230.1 58.4 38.8 Other Revenues from Contracts 30.2 46.9 11.8 26.7 56.2 11.3 32.9 43.6 14.2 Amortization of/(Reserve for) Revenues 72.7 — — (76.1) — — — — 4.6 Total Revenues from Contracts 5,343.2 4,127.3 1,659.6 4,238.9 3,541.6 1,387.6 4,044.7 3,327.5 1,241.3 Alternative Revenue Programs 56.5 0.7 20.1 (78.9) (15.1) (17.4) (4.2) 54.5 2.6 Other Revenues 1.8 7.2 2.9 0.4 3.4 1.9 2.2 3.5 0.6 Eliminations (583.8) (552.1) (207.8) (523.0) (473.5) (194.9) (495.2) (444.4) (165.4) Total Operating Revenues $ 4,817.7 $ 3,583.1 $ 1,474.8 $ 3,637.4 $ 3,056.4 $ 1,177.2 $ 3,547.5 $ 2,941.1 $ 1,079.1

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Components of Basic and Diluted EPS	The following table sets forth the components of basic and diluted EPS: Eversource (Millions of Dollars, except share information) For the Years Ended December 31, 2022 2021 2020 Net Income Attributable to Common Shareholders $ 1,404.9 $ 1,220.5 $ 1,205.2 Weighted Average Common Shares Outstanding: Basic 346,783,444 343,972,926 338,836,147 Dilutive Effect of: Share-Based Compensation Awards and Other 463,324 658,130 738,994 Equity Forward Sale Agreement — — 271,921 Total Dilutive Effect 463,324 658,130 1,010,915 Diluted 347,246,768 344,631,056 339,847,062 Basic EPS $ 4.05 $ 3.55 $ 3.56 Diluted EPS $ 4.05 $ 3.54 $ 3.55

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2022
Segment Reporting [Abstract]
Summary of Segment Information and Segmented Total Assets	Eversource's segment information is as follows: For the Year Ended December 31, 2022 Eversource (Millions of Dollars) Electric Natural Gas Electric Transmission Water Distribution Other Eliminations Total Operating Revenues $ 9,405.3 $ 2,215.6 $ 1,808.7 $ 222.5 $ 1,435.5 $ (2,798.3) $ 12,289.3 Depreciation and Amortization (970.4) (157.6) (337.4) (50.9) (132.6) 5.8 (1,643.1) Other Operating Expenses (7,663.7) (1,727.0) (548.4) (111.8) (1,189.1) 2,792.0 (8,448.0) Operating Income 771.2 331.0 922.9 59.8 113.8 (0.5) 2,198.2 Interest Expense (253.1) (71.4) (145.5) (34.7) (247.8) 74.2 (678.3) Interest Income 45.1 10.2 0.5 — 66.3 (71.6) 50.5 Other Income, Net 180.4 33.6 37.9 8.5 1,600.8 (1,565.6) 295.6 Income Tax (Expense)/Benefit (146.2) (69.2) (216.3) 3.2 (25.1) — (453.6) Net Income 597.4 234.2 599.5 36.8 1,508.0 (1,563.5) 1,412.4 Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income Attributable to Common Shareholders $ 592.8 $ 234.2 $ 596.6 $ 36.8 $ 1,508.0 $ (1,563.5) $ 1,404.9 Total Assets (as of) $ 27,365.0 $ 8,084.9 $ 13,369.5 $ 2,783.8 $ 26,365.2 $ (24,737.5) $ 53,230.9 Cash Flows Used for Investments in Plant $ 1,172.6 $ 710.3 $ 1,144.0 $ 154.4 $ 260.6 $ — $ 3,441.9 For the Year Ended December 31, 2021 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Operating Revenues $ 7,423.6 $ 1,789.6 $ 1,634.6 $ 211.3 $ 1,354.0 $ (2,550.0) $ 9,863.1 Depreciation and Amortization (737.8) (142.3) (300.3) (46.1) (113.1) 4.6 (1,335.0) Other Operating Expenses (5,970.0) (1,345.4) (496.2) (101.4) (1,170.4) 2,548.6 (6,534.8) Operating Income 715.8 301.9 838.1 63.8 70.5 3.2 1,993.3 Interest Expense (236.4) (58.6) (133.2) (32.0) (168.8) 46.6 (582.4) Interest Income 20.7 4.5 2.2 — 46.0 (47.8) 25.6 Other Income, Net 78.1 17.9 19.8 3.3 1,363.9 (1,347.3) 135.7 Income Tax (Expense)/Benefit (103.5) (60.9) (179.4) 1.7 (2.1) — (344.2) Net Income 474.7 204.8 547.5 36.8 1,309.5 (1,345.3) 1,228.0 Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income Attributable to Common Shareholders $ 470.1 $ 204.8 $ 544.6 $ 36.8 $ 1,309.5 $ (1,345.3) $ 1,220.5 Total Assets (as of) $ 25,411.2 $ 7,215.9 $ 12,377.8 $ 2,551.1 $ 22,674.7 $ (21,738.6) $ 48,492.1 Cash Flows Used for Investments in Plant $ 1,053.3 $ 721.1 $ 1,024.1 $ 137.2 $ 239.4 $ — $ 3,175.1 For the Year Ended December 31, 2020 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Operating Revenues $ 7,132.3 $ 1,208.7 $ 1,536.1 $ 215.4 $ 1,235.9 $ (2,424.0) $ 8,904.4 Depreciation and Amortization (657.0) (87.9) (278.1) (44.2) (93.5) 1.6 (1,159.1) Other Operating Expenses (5,642.3) (913.8) (470.0) (86.6) (1,071.9) 2,428.0 (5,756.6) Operating Income 833.0 207.0 788.0 84.6 70.5 5.6 1,988.7 Interest Expense (216.0) (40.0) (126.8) (32.9) (161.0) 38.3 (538.4) Interest Income 3.2 0.9 4.7 — 37.8 (41.8) 4.8 Other Income, Net 58.0 3.1 23.3 2.0 1,382.9 (1,365.5) 103.8 Income Tax (Expense)/Benefit (129.6) (36.9) (183.8) (12.5) 16.6 — (346.2) Net Income 548.6 134.1 505.4 41.2 1,346.8 (1,363.4) 1,212.7 Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income Attributable to Common Shareholders $ 544.0 $ 134.1 $ 502.5 $ 41.2 $ 1,346.8 $ (1,363.4) $ 1,205.2 Cash Flows Used for Investments in Plant $ 1,079.0 $ 494.4 $ 1,004.6 $ 118.8 $ 246.2 $ — $ 2,943.0

ACQUISITION OF ASSETS OF COLU_2

ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS (Tables)	12 Months Ended
	Dec. 31, 2022
Business Combination and Asset Acquisition [Abstract]
Summary of Unaudited Pro Forma Financial Information	Pro forma net income excludes the impact of assets and liabilities not assumed by Eversource and non-recurring costs associated with the transaction. (Pro forma amounts in millions, except share amounts) For the Year Ended Operating Revenues $ 9,273 Net Income Attributable to Common Shareholders 1,265 Basic EPS 3.73 Diluted EPS 3.72

GOODWILL (Tables)

GOODWILL (Tables)	12 Months Ended
	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Goodwill by Reportable Segment	The following table presents Eversource’s goodwill by reportable segment: (Millions of Dollars) Electric Electric Natural Gas Water Total Balance as of January 1, 2021 $ 2,543.6 $ 576.8 $ 441.4 $ 884.2 $ 4,446.0 CMA Measurement Period Adjustments — — 9.6 — 9.6 Acquisition of NESC — — — 21.7 21.7 Balance as of December 31, 2021 $ 2,543.6 $ 576.8 $ 451.0 $ 905.9 $ 4,477.3 NESC Measurement Period Adjustments — — — 0.5 0.5 Acquisition of TWC — — — 44.8 44.8 Balance as of December 31, 2022 $ 2,543.6 $ 576.8 $ 451.0 $ 951.2 $ 4,522.6

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Thousands, customer in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) customer regulatedUtility	Dec. 31, 2020 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Oct. 01, 2021 USD ($)	Dec. 31, 2019 USD ($)
Summary of Accounting Policies [Line Items]
Number of electric and natural gas customers | customer	4.4
Goodwill	$ 4,522,632	$ 4,446,000		$ 4,477,269
Allowance for uncollectible accounts for late fees and other receivable amounts	486,297	358,900		417,406		$ 224,800
Bill of forgiveness	521,752	264,950		221,008		117,063
Cash equivalents	374,600			66,800
Charitable contributions	8,000	6,400
Energy Relief Fund
Summary of Accounting Policies [Line Items]
Restricted cash, current	20,000
Restricted cash, noncurrent	15,900
Restricted cash				41,500
Electric Transmission
Summary of Accounting Policies [Line Items]
Goodwill	576,800	576,800		576,800
Retail (Non-Hardship), Wholesale, and Other
Summary of Accounting Policies [Line Items]
Allowance for uncollectible accounts for late fees and other receivable amounts	201,900	164,100		191,300		81,500
CL&P
Summary of Accounting Policies [Line Items]
Allowance for uncollectible accounts for late fees and other receivable amounts	$ 225,320	157,400		181,319		97,300
Period of accounts receivable recoverable under financial or medical duress	180 days
Maximum loans receivable outstanding	$ 55,000
Loans transferred receivable current	9,100			10,500
Loans transferred receivable non-current	13,000			8,300
Bill of forgiveness	20,327	99,809		74,788		4,971
Cash equivalents	11,300			55,800
Long term receivable	25,000			25,000
CL&P | Customer Assistance Fund
Summary of Accounting Policies [Line Items]
Bill of forgiveness			$ 10,000
CL&P | Unfavorable Regulatory Action
Summary of Accounting Policies [Line Items]
Customer assistance initiatives					$ 10,000
CL&P | Retail (Non-Hardship), Wholesale, and Other
Summary of Accounting Policies [Line Items]
Allowance for uncollectible accounts for late fees and other receivable amounts	$ 36,400	28,300		36,700		17,200
Yankee Gas Services Company
Summary of Accounting Policies [Line Items]
Period of accounts receivable recoverable under financial or medical duress	90 days
NSTAR Electric
Summary of Accounting Policies [Line Items]
Allowance for uncollectible accounts for late fees and other receivable amounts	$ 94,958	91,600		97,005		75,400
Bill of forgiveness	345,293	17,410		18,179		6,312
Cash equivalents	327,700			700
Long term receivable	5,500			5,500
NSTAR Electric | Cash Infusion From Parent
Summary of Accounting Policies [Line Items]
Cash equivalents	327,000
NSTAR Electric | Retail (Non-Hardship), Wholesale, and Other
Summary of Accounting Policies [Line Items]
Allowance for uncollectible accounts for late fees and other receivable amounts	51,300	51,900		53,700		31,500
PSNH
Summary of Accounting Policies [Line Items]
Allowance for uncollectible accounts for late fees and other receivable amounts	29,236	17,200		24,331		10,500
Bill of forgiveness	36,812	$ 39,555		35,126		$ 36,688
Cash equivalents	100			0
Long term receivable	$ 3,800			3,800
Connecticut, Massachusetts and New Hampshire
Summary of Accounting Policies [Line Items]
Number of regulated utilities | regulatedUtility	12
COVID 19
Summary of Accounting Policies [Line Items]
Allowance for uncollectible accounts for late fees and other receivable amounts	$ 50,900			55,300
COVID 19 | CL&P
Summary of Accounting Policies [Line Items]
Allowance for uncollectible accounts for late fees and other receivable amounts	16,000			23,900
COVID 19 | NSTAR Electric
Summary of Accounting Policies [Line Items]
Allowance for uncollectible accounts for late fees and other receivable amounts	$ 4,100			$ 9,000

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Allowance for Uncollectible Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 417,406	$ 358,900	$ 224,800
Increase due to CMA acquisition			24,200
Uncollectible Expense	61,876	60,886	53,461
Uncollectible Costs Deferred	112,500	110,600	97,000
Write-Offs	(124,000)	(129,700)	(78,000)
Recoveries Collected	18,500	16,700	13,600
Ending Balance	486,297	417,406	358,900
Restatement Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance		23,800	23,800
Ending Balance			23,800
Hardship Accounts
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	226,100	194,800	143,300
Increase due to CMA acquisition			0
Uncollectible Expense	0	0	0
Uncollectible Costs Deferred	77,800	51,900	43,100
Write-Offs	(21,300)	(22,000)	(14,700)
Recoveries Collected	1,800	1,400	1,500
Ending Balance	284,400	226,100	194,800
Hardship Accounts | Restatement Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			21,600
Retail (Non-Hardship), Wholesale, and Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	191,300	164,100	81,500
Increase due to CMA acquisition			24,200
Uncollectible Expense	61,900	60,900	53,500
Uncollectible Costs Deferred	34,700	58,700	53,900
Write-Offs	(102,700)	(107,700)	(63,300)
Recoveries Collected	16,700	15,300	12,100
Ending Balance	201,900	191,300	164,100
Retail (Non-Hardship), Wholesale, and Other | Restatement Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			2,200
CL&P
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	181,319	157,400	97,300
Increase due to CMA acquisition			0
Uncollectible Expense	15,578	13,495	12,882
Uncollectible Costs Deferred	59,500	57,800	49,000
Write-Offs	(38,300)	(54,200)	(29,700)
Recoveries Collected	7,200	6,800	5,700
Ending Balance	225,320	181,319	157,400
CL&P | Restatement Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance		22,200	22,200
Ending Balance			22,200
CL&P | Hardship Accounts
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	144,600	129,100	80,100
Increase due to CMA acquisition			0
Uncollectible Expense	0	0	0
Uncollectible Costs Deferred	58,300	32,300	38,200
Write-Offs	(15,300)	(18,000)	(11,900)
Recoveries Collected	1,300	1,200	1,400
Ending Balance	188,900	144,600	129,100
CL&P | Hardship Accounts | Restatement Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			21,300
CL&P | Retail (Non-Hardship), Wholesale, and Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	36,700	28,300	17,200
Increase due to CMA acquisition			0
Uncollectible Expense	15,600	13,500	12,900
Uncollectible Costs Deferred	1,200	25,500	10,800
Write-Offs	(23,000)	(36,200)	(17,800)
Recoveries Collected	5,900	5,600	4,300
Ending Balance	36,400	36,700	28,300
CL&P | Retail (Non-Hardship), Wholesale, and Other | Restatement Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			900
NSTAR Electric
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	97,005	91,600	75,400
Increase due to CMA acquisition			0
Uncollectible Expense	21,550	16,649	15,293
Uncollectible Costs Deferred	12,400	20,100	24,700
Write-Offs	(42,300)	(37,000)	(27,200)
Recoveries Collected	6,300	5,700	4,700
Ending Balance	94,958	97,005	91,600
NSTAR Electric | Restatement Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance		(1,300)	(1,300)
Ending Balance			(1,300)
NSTAR Electric | Hardship Accounts
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	43,300	39,700	43,900
Increase due to CMA acquisition			0
Uncollectible Expense	0	0	0
Uncollectible Costs Deferred	1,500	4,300	(1,700)
Write-Offs	(1,100)	(700)	(900)
Recoveries Collected	0	0	0
Ending Balance	43,700	43,300	39,700
NSTAR Electric | Hardship Accounts | Restatement Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			(1,600)
NSTAR Electric | Retail (Non-Hardship), Wholesale, and Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	53,700	51,900	31,500
Increase due to CMA acquisition			0
Uncollectible Expense	21,600	16,600	15,300
Uncollectible Costs Deferred	10,900	15,800	26,400
Write-Offs	(41,200)	(36,300)	(26,300)
Recoveries Collected	6,300	5,700	4,700
Ending Balance	51,300	53,700	51,900
NSTAR Electric | Retail (Non-Hardship), Wholesale, and Other | Restatement Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance			300
PSNH
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	24,331	17,200	10,500
Increase due to CMA acquisition			0
Uncollectible Expense	9,211	13,113	5,164
Uncollectible Costs Deferred	2,500	3,100	7,400
Write-Offs	(7,700)	(10,000)	(6,900)
Recoveries Collected	900	900	700
Ending Balance	$ 29,236	24,331	17,200
PSNH | Restatement Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance		$ 300	300
Ending Balance			$ 300

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Materials, Supplies, Natural Gas, and REC Inventory (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Public Utilities, Inventory [Line Items]
Total	$ 374.4	$ 267.5
Materials and Supplies
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	221	148.9
Natural Gas
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	95.9	56.2
RECs
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	57.5	62.4
CL&P
Public Utilities, Inventory [Line Items]
Total	88.2	60.3
CL&P | Materials and Supplies
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	88.2	60.3
CL&P | Natural Gas
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	0	0
CL&P | RECs
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	0	0
NSTAR Electric
Public Utilities, Inventory [Line Items]
Total	138.4	116.7
NSTAR Electric | Materials and Supplies
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	81	55
NSTAR Electric | Natural Gas
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	0	0
NSTAR Electric | RECs
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	57.4	61.7
PSNH
Public Utilities, Inventory [Line Items]
Total	34.5	25.9
PSNH | Materials and Supplies
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	34.4	25.2
PSNH | Natural Gas
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	0	0
PSNH | RECs
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	$ 0.1	$ 0.7

SUMMARY OF SIGNIFICANT ACCOUN_7

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Operating Expenses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Eversource - Cost of Natural Gas	$ 1,010.2	$ 718.6	$ 464.2

SUMMARY OF SIGNIFICANT ACCOUN_8

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of AFUDC and Weighted Average AFUDC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Components of Other Operating Costs and Expense [Line Items]
Borrowed Funds	$ 21.8	$ 18.4	$ 23.7
Equity Funds	47.3	37.3	42
Total AFUDC	$ 69.1	$ 55.7	$ 65.7
Average AFUDC Rate (in percent)	4.70%	4.20%	5%
CL&P
Components of Other Operating Costs and Expense [Line Items]
Borrowed Funds	$ 4.8	$ 2.9	$ 6.6
Equity Funds	13.6	7.7	13.8
Total AFUDC	$ 18.4	$ 10.6	$ 20.4
Average AFUDC Rate (in percent)	6.60%	5%	5.90%
NSTAR Electric
Components of Other Operating Costs and Expense [Line Items]
Borrowed Funds	$ 10.7	$ 9	$ 9.1
Equity Funds	24.6	20.4	21.5
Total AFUDC	$ 35.3	$ 29.4	$ 30.6
Average AFUDC Rate (in percent)	5.40%	4.90%	5.70%
PSNH
Components of Other Operating Costs and Expense [Line Items]
Borrowed Funds	$ 1.4	$ 0.8	$ 2.1
Equity Funds	2.5	1.6	4.2
Total AFUDC	$ 3.9	$ 2.4	$ 6.3
Average AFUDC Rate (in percent)	2.60%	2.50%	4.70%

SUMMARY OF SIGNIFICANT ACCOUN_9

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Other Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Summary of Accounting Policies [Line Items]
Other Income, Net	$ 346,088	$ 161,282	$ 108,590
Unrealized gain associated with investment	22,900	14,200	14,200
Renewable Energy Fund
Summary of Accounting Policies [Line Items]
Other-than-temporary impairment		2,800	2,800
Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion
Summary of Accounting Policies [Line Items]
Other Income, Net	219,800	84,400	44,400
AFUDC Equity
Summary of Accounting Policies [Line Items]
Other Income, Net	47,300	37,300	42,000
Equity in Earnings of Unconsolidated Affiliates
Summary of Accounting Policies [Line Items]
Other Income, Net	22,900	14,200	14,200
Unrealized gain associated with investment	12,200	2,100	2,400
Investment (Loss)/Income
Summary of Accounting Policies [Line Items]
Other Income, Net	1,900	(200)	1,100
Interest Income
Summary of Accounting Policies [Line Items]
Other Income, Net	50,500	25,600	4,800
Other
Summary of Accounting Policies [Line Items]
Other Income, Net	1,100	(100)	300
Gain on Sale of Property
Summary of Accounting Policies [Line Items]
Other Income, Net	2,600	100	1,800
CL&P
Summary of Accounting Policies [Line Items]
Other Income, Net	83,252	30,187	20,774
CL&P | Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion
Summary of Accounting Policies [Line Items]
Other Income, Net	64,400	15,200	3,800
CL&P | AFUDC Equity
Summary of Accounting Policies [Line Items]
Other Income, Net	13,600	7,700	13,800
CL&P | Investment (Loss)/Income
Summary of Accounting Policies [Line Items]
Other Income, Net	(1,300)	1,300	1,100
CL&P | Interest Income
Summary of Accounting Policies [Line Items]
Other Income, Net	6,500	5,900	2,000
CL&P | Other
Summary of Accounting Policies [Line Items]
Other Income, Net	100	100	100
NSTAR Electric
Summary of Accounting Policies [Line Items]
Other Income, Net	142,661	74,844	52,017
NSTAR Electric | Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion
Summary of Accounting Policies [Line Items]
Other Income, Net	85,500	40,200	29,300
NSTAR Electric | AFUDC Equity
Summary of Accounting Policies [Line Items]
Other Income, Net	24,600	20,400	21,500
NSTAR Electric | Investment (Loss)/Income
Summary of Accounting Policies [Line Items]
Other Income, Net	1,200	100	(800)
NSTAR Electric | Interest Income
Summary of Accounting Policies [Line Items]
Other Income, Net	30,700	13,400	900
NSTAR Electric | Other
Summary of Accounting Policies [Line Items]
Other Income, Net	700	700	1,100
PSNH
Summary of Accounting Policies [Line Items]
Other Income, Net	32,666	14,565	13,786
PSNH | Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion
Summary of Accounting Policies [Line Items]
Other Income, Net	26,800	10,300	7,000
PSNH | AFUDC Equity
Summary of Accounting Policies [Line Items]
Other Income, Net	2,500	1,600	4,200
PSNH | Investment (Loss)/Income
Summary of Accounting Policies [Line Items]
Other Income, Net	200	100	100
PSNH | Interest Income
Summary of Accounting Policies [Line Items]
Other Income, Net	3,100	2,400	2,400
PSNH | Other
Summary of Accounting Policies [Line Items]
Other Income, Net	$ 100	$ 200	$ 100

SUMMARY OF SIGNIFICANT ACCOU_10

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Other Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Summary of Accounting Policies [Line Items]
Excise and sales taxes	$ 194.7	$ 181.9	$ 170.6
CL&P
Summary of Accounting Policies [Line Items]
Excise and sales taxes	$ 166.1	$ 158.1	$ 149.9

SUMMARY OF SIGNIFICANT ACCOU_11

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash Paid During the Year for:
Interest, Net of Amounts Capitalized	$ 636.2	$ 568.7	$ 518
Income Taxes	77.9	121.6	48.9
Non-Cash Investing Activities:
Plant Additions Included in Accounts Payable (As of)	586.9	467.9	367.2
CL&P
Cash Paid During the Year for:
Interest, Net of Amounts Capitalized	167.2	161.5	149
Income Taxes	117.6	38.4	10.9
Non-Cash Investing Activities:
Plant Additions Included in Accounts Payable (As of)	131.8	110.6	101.8
NSTAR Electric
Cash Paid During the Year for:
Interest, Net of Amounts Capitalized	152.8	141.6	129.4
Income Taxes	23.8	74.2	110.7
Non-Cash Investing Activities:
Plant Additions Included in Accounts Payable (As of)	184.3	120	103.2
PSNH
Cash Paid During the Year for:
Interest, Net of Amounts Capitalized	58.3	56.5	54.5
Income Taxes	58.3	51.1	34.2
Non-Cash Investing Activities:
Plant Additions Included in Accounts Payable (As of)	$ 76.2	$ 68.7	$ 33.3

SUMMARY OF SIGNIFICANT ACCOU_12

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and Cash Equivalents as reported on the Balance Sheets	$ 374,600	$ 66,800
Cash, Cash Equivalents and Restricted Cash as reported on the Statements of Cash Flows	521,752	221,008	$ 264,950	$ 117,063
CL&P
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and Cash Equivalents as reported on the Balance Sheets	11,300	55,800
Cash, Cash Equivalents and Restricted Cash as reported on the Statements of Cash Flows	20,327	74,788	99,809	4,971
NSTAR Electric
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and Cash Equivalents as reported on the Balance Sheets	327,700	700
Cash, Cash Equivalents and Restricted Cash as reported on the Statements of Cash Flows	345,293	18,179	17,410	6,312
PSNH
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and Cash Equivalents as reported on the Balance Sheets	100	0
Cash, Cash Equivalents and Restricted Cash as reported on the Statements of Cash Flows	36,812	35,126	$ 39,555	$ 36,688
Special Deposits
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	102,200	78,200
Special Deposits | CL&P
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	8,800	18,700
Special Deposits | NSTAR Electric
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	17,500	17,400
Special Deposits | PSNH
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	33,100	31,400
Marketable Securities
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	25,400	31,300
Marketable Securities | CL&P
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	200	300
Marketable Securities | NSTAR Electric
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	100	100
Marketable Securities | PSNH
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	400	500
Other Long-Term Assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	19,600	44,700
Other Long-Term Assets | CL&P
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	0	0
Other Long-Term Assets | NSTAR Electric
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	0	0
Other Long-Term Assets | PSNH
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	$ 3,200	$ 3,200

REGULATORY ACCOUNTING - Compone

REGULATORY ACCOUNTING - Components of Regulatory Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Regulatory Assets [Line Items]
Total Regulatory Assets	$ 5,578,300	$ 5,715,800
Less:  Current Portion	1,335,491	1,129,093
Total Long-Term Regulatory Assets	4,242,794	4,586,709
Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	921,700	1,481,000
Storm Costs, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	1,379,100	1,102,700
Regulatory Tracking Mechanisms
Regulatory Assets [Line Items]
Total Regulatory Assets	1,075,300	1,050,500
Income Taxes, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	853,300	790,700
Securitized Stranded Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	435,700	478,900
Goodwill-related
Regulatory Assets [Line Items]
Total Regulatory Assets	281,000	297,800
Derivative Liabilities
Regulatory Assets [Line Items]
Total Regulatory Assets	181,800	249,200
Asset Retirement Obligations
Regulatory Assets [Line Items]
Total Regulatory Assets	127,900	115,000
Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	322,500	150,000
CL&P
Regulatory Assets [Line Items]
Total Regulatory Assets	1,907,800	2,084,800
Less:  Current Portion	314,089	371,609
Total Long-Term Regulatory Assets	1,593,693	1,713,161
CL&P | Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	156,700	272,400
CL&P | Storm Costs, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	799,300	695,600
CL&P | Regulatory Tracking Mechanisms
Regulatory Assets [Line Items]
Total Regulatory Assets	216,800	333,600
CL&P | Income Taxes, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	491,100	470,500
CL&P | Securitized Stranded Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
CL&P | Goodwill-related
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
CL&P | Derivative Liabilities
Regulatory Assets [Line Items]
Total Regulatory Assets	181,800	249,200
CL&P | Asset Retirement Obligations
Regulatory Assets [Line Items]
Total Regulatory Assets	35,900	33,600
CL&P | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	26,200	29,900
NSTAR Electric
Regulatory Assets [Line Items]
Total Regulatory Assets	1,714,400	1,579,200
Less:  Current Portion	492,759	443,956
Total Long-Term Regulatory Assets	1,221,619	1,135,231
NSTAR Electric | Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	299,500	395,500
NSTAR Electric | Storm Costs, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	484,400	341,300
NSTAR Electric | Regulatory Tracking Mechanisms
Regulatory Assets [Line Items]
Total Regulatory Assets	391,500	376,600
NSTAR Electric | Income Taxes, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	115,600	112,600
NSTAR Electric | Securitized Stranded Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
NSTAR Electric | Goodwill-related
Regulatory Assets [Line Items]
Total Regulatory Assets	241,200	255,700
NSTAR Electric | Derivative Liabilities
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
NSTAR Electric | Asset Retirement Obligations
Regulatory Assets [Line Items]
Total Regulatory Assets	68,200	59,800
NSTAR Electric | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	114,000	37,700
PSNH
Regulatory Assets [Line Items]
Total Regulatory Assets	696,200	786,400
Less:  Current Portion	102,240	107,169
Total Long-Term Regulatory Assets	593,974	679,182
PSNH | Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	56,600	118,900
PSNH | Storm Costs, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	95,400	65,800
PSNH | Regulatory Tracking Mechanisms
Regulatory Assets [Line Items]
Total Regulatory Assets	73,700	85,400
PSNH | Income Taxes, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	16,000	17,500
PSNH | Securitized Stranded Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	435,700	478,900
PSNH | Goodwill-related
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
PSNH | Derivative Liabilities
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
PSNH | Asset Retirement Obligations
Regulatory Assets [Line Items]
Total Regulatory Assets	4,400	4,100
PSNH | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	$ 14,400	$ 15,800

REGULATORY ACCOUNTING - Narrati

REGULATORY ACCOUNTING - Narrative (Details)

4 Months Ended

12 Months Ended

Jan. 01, 2023 USD ($)

Nov. 01, 2022 USD ($)

Apr. 30, 2023 USD ($)

Dec. 31, 2022 USD ($) storm

Dec. 31, 2021 USD ($)

Dec. 31, 2020 USD ($)

Mar. 31, 2022 USD ($)

Oct. 01, 2021 USD ($)

May 06, 2021 USD ($)

Mar. 31, 2021 USD ($)

Dec. 31, 2019 USD ($)

May 31, 2018 USD ($)

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

$ 210,800,000

$ 252,500,000

Deferred costs related to uncollectible expense

29,800,000

33,000,000

Regulatory Liabilities

890,786,000

602,432,000

Gain (loss) related to litigation settlement

72,041,000

(81,274,000)

$ 0

Regulatory assets

5,578,300,000

5,715,800,000

Increase (decrease) in regulatory assets

205,294,000

314,211,000

516,411,000

Cash, Cash Equivalents and Restricted Cash as reported on the Statements of Cash Flows

521,752,000

221,008,000

264,950,000

$ 117,063,000

FERC ROE Complaints

Regulatory Assets [Line Items]

Cumulative pre-tax reserves which include impact of refunds given to customers

39,100,000

Unfavorable Regulatory Action

Regulatory Assets [Line Items]

Gain (loss) related to litigation settlement

(103,600,000)

Unfavorable Regulatory Action | Oil and Gas, Operation and Maintenance

Regulatory Assets [Line Items]

Gain (loss) related to litigation settlement

(10,000,000)

Deferred Pre-Staging And Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

399,000,000

Deferred Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

$ 1,400,000,000

Goodwill-related

Regulatory Assets [Line Items]

Recovery period (in years)

40 years

Remaining amortization (in years)

17 years

Regulatory assets

$ 281,000,000

297,800,000

Storm Costs, Net

Regulatory Assets [Line Items]

Regulatory assets

1,379,100,000

1,102,700,000

PSNH

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

1,000,000

3,400,000

Equity return not recorded on the balance sheet

4,100,000

5,000,000

Regulatory Liabilities

161,963,000

120,176,000

Regulatory assets

696,200,000

786,400,000

Increase (decrease) in regulatory assets

(53,181,000)

(32,587,000)

45,830,000

Cash, Cash Equivalents and Restricted Cash as reported on the Statements of Cash Flows

36,812,000

35,126,000

39,555,000

36,688,000

PSNH | FERC ROE Complaints

Regulatory Assets [Line Items]

Cumulative pre-tax reserves which include impact of refunds given to customers

3,100,000

PSNH | Deferred Pre-Staging And Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

55,000,000

PSNH | Deferred Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

98,000,000

PSNH | Goodwill-related

Regulatory Assets [Line Items]

Regulatory assets

0

0

PSNH | Storm Costs, Net

Regulatory Assets [Line Items]

Regulatory assets

95,400,000

65,800,000

CL&P

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

135,900,000

114,900,000

Deferred costs related to uncollectible expense

11,800,000

18,000,000

Regulatory Liabilities

336,048,000

266,489,000

Gain (loss) related to litigation settlement

72,041,000

(81,274,000)

0

Regulatory assets

1,907,800,000

2,084,800,000

Increase (decrease) in regulatory assets

144,793,000

152,775,000

279,941,000

Cash, Cash Equivalents and Restricted Cash as reported on the Statements of Cash Flows

20,327,000

74,788,000

99,809,000

4,971,000

CL&P | Energy Assistance Program

Regulatory Assets [Line Items]

Restricted cash

10,000,000

CL&P | Customer Assistance Fund

Regulatory Assets [Line Items]

Cash, Cash Equivalents and Restricted Cash as reported on the Statements of Cash Flows

$ 10,000,000

CL&P | Forecast

Regulatory Assets [Line Items]

Average monthly bill

$ 10

Public utilities, approved rate increase (decrease), net revenues generated

$ 90,000,000

CL&P | FERC ROE Complaints

Regulatory Assets [Line Items]

Cumulative pre-tax reserves which include impact of refunds given to customers

21,400,000

CL&P | Unfavorable Regulatory Action

Regulatory Assets [Line Items]

Loss contingency, estimate of possible earnings impact, non-compliance with performance standards

$ 28,400,000

$ 28,400,000

Period credits are issued to customers (in years)

1 year

Regulatory Liabilities

75,000,000

75,000,000

Customer credits

$ 65,000,000

Customer assistance initiatives

$ 10,000,000

CL&P | Unfavorable Regulatory Action | Oil and Gas, Operation and Maintenance

Regulatory Assets [Line Items]

Gain (loss) related to litigation settlement

(10,000,000)

CL&P | Deferred Pre-Staging And Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

163,000,000

CL&P | Deferred Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

807,000,000

CL&P | Deferred Storm Restoration Costs | Tropical Storm Isaias

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

235,000,000

CL&P | Goodwill-related

Regulatory Assets [Line Items]

Regulatory assets

0

0

CL&P | Storm Costs, Net

Regulatory Assets [Line Items]

Regulatory assets

799,300,000

695,600,000

NSTAR Electric

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

19,800,000

85,000,000

Deferred costs related to uncollectible expense

2,200,000

6,100,000

Regulatory Liabilities

$ 373,221,000

228,248,000

Renewal term of performance-based ratemaking plan (in years)

5 years

Extension period (in years)

5 years

Historical average term of capital additions (in years)

5 years

Authorized regulatory ROE (in percent)

9.80%

Authorized common equity ratio (in percent)

53.20%

Regulatory assets

$ 1,714,400,000

1,579,200,000

Increase (decrease) in regulatory assets

$ 88,220,000

79,075,000

186,081,000

Storms in a calendar year | storm

8

Storms recovered at base rate | storm

6

Number of additional storms | storm

2

Cash, Cash Equivalents and Restricted Cash as reported on the Statements of Cash Flows

$ 345,293,000

18,179,000

$ 17,410,000

$ 6,312,000

NSTAR Electric | Subsequent Event

Regulatory Assets [Line Items]

Rate increase approved

$ 64,000,000

NSTAR Electric | FERC ROE Complaints

Regulatory Assets [Line Items]

Cumulative pre-tax reserves which include impact of refunds given to customers

14,600,000

NSTAR Electric | Deferred Pre-Staging And Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

181,000,000

NSTAR Electric | Deferred Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

492,000,000

NSTAR Electric | Goodwill-related

Regulatory Assets [Line Items]

Regulatory assets

241,200,000

255,700,000

NSTAR Electric | Storm Costs, Net

Regulatory Assets [Line Items]

Regulatory assets

484,400,000

$ 341,300,000

NSTAR Electric | Storm Fund Contribution

Regulatory Assets [Line Items]

Regulatory assets

10,000,000

Increase (decrease) in regulatory assets

31,000,000

NSTAR Electric | Storm Threshold Costs

Regulatory Assets [Line Items]

Regulatory assets

1,300,000

NSTAR Electric | Recovery of Storm Costs | Subsequent Event

Regulatory Assets [Line Items]

Regulatory assets

$ 162,100,000

Recovery period of regulatory asset (in years)

5 years

NSTAR Electric | Recovery of exogenous storms

Regulatory Assets [Line Items]

Regulatory assets

$ 220,900,000

Recovery period of regulatory asset (in years)

5 years

NSTAR Electric | Recovery of historical exogenous property taxes from 2020 - 2022 | Subsequent Event

Regulatory Assets [Line Items]

Regulatory assets

$ 30,800,000

Recovery period of regulatory asset (in years)

2 years

NSTAR Electric | Recovery of historical exogenous property taxes from 2012 - 2015 | Subsequent Event

Regulatory Assets [Line Items]

Regulatory assets

$ 8,300,000

Recovery period of regulatory asset (in years)

5 years

NSTAR Gas

Regulatory Assets [Line Items]

Rate increase approved

$ 21,700,000

NSTAR Gas | Exogenous Property Taxes

Regulatory Assets [Line Items]

Rate increase approved

4,500,000

NSTAR Gas | Mitigation Plan

Regulatory Assets [Line Items]

Rate increase approved

5,400,000

NSTAR Gas | Recovery of Exogenous Property Taxes

Regulatory Assets [Line Items]

Regulatory assets

$ 8,200,000

Recovery period of regulatory asset (in years)

2 years

EGMA

Regulatory Assets [Line Items]

Rate increase approved

$ 6,700,000

EGMA | Tax Act Credit Factor

Regulatory Assets [Line Items]

Rate increase approved

3,300,000

EGMA | Recovery of Exogenous Property Taxes

Regulatory Assets [Line Items]

Regulatory assets

$ 8,600,000

Recovery period of regulatory asset (in years)

2 years

Rate Reduction Bonds | PSNH

Regulatory Assets [Line Items]

Amount of securitized rate reduction bonds issued

$ 635,700,000

REGULATORY ACCOUNTING - Compo_2

REGULATORY ACCOUNTING - Components of Regulatory Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 4,821,100	$ 4,468,700
Less:  Current Portion	890,786	602,432
Total Long-Term Regulatory Liabilities	3,930,305	3,866,251
EDIT due to Tax Cuts and Jobs Act of 2017
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	2,619,300	2,685,200
Cost of Removal
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	670,600	649,600
Regulatory Tracking Mechanisms
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	890,800	448,400
Deferred Portion of Non-Service Income Components of Pension, SERP and PBOP
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	270,900	148,300
Benefit Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	55,400	133,500
AFUDC - Transmission
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	98,200	81,000
CL&P Settlement Agreement and Storm Performance Penalty
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	81,300
Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	215,900	241,400
CL&P
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	1,599,400	1,459,800
Less:  Current Portion	336,048	266,489
Total Long-Term Regulatory Liabilities	1,263,396	1,193,259
CL&P | EDIT due to Tax Cuts and Jobs Act of 2017
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	983,600	996,100
CL&P | Cost of Removal
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	130,800	100,100
CL&P | Regulatory Tracking Mechanisms
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	361,000	182,000
CL&P | Deferred Portion of Non-Service Income Components of Pension, SERP and PBOP
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	34,500	12,000
CL&P | Benefit Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	700	0
CL&P | AFUDC - Transmission
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	48,200	43,200
CL&P | CL&P Settlement Agreement and Storm Performance Penalty
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	81,300
CL&P | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	40,600	45,100
NSTAR Electric
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	1,921,300	1,787,300
Less:  Current Portion	373,221	228,248
Total Long-Term Regulatory Liabilities	1,548,081	1,559,072
NSTAR Electric | EDIT due to Tax Cuts and Jobs Act of 2017
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	944,300	984,500
NSTAR Electric | Cost of Removal
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	405,300	381,000
NSTAR Electric | Regulatory Tracking Mechanisms
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	336,100	185,100
NSTAR Electric | Deferred Portion of Non-Service Income Components of Pension, SERP and PBOP
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	139,700	90,700
NSTAR Electric | Benefit Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	31,400	107,400
NSTAR Electric | AFUDC - Transmission
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	50,000	37,800
NSTAR Electric | CL&P Settlement Agreement and Storm Performance Penalty
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
NSTAR Electric | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	14,500	800
PSNH
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	553,600	501,600
Less:  Current Portion	161,963	120,176
Total Long-Term Regulatory Liabilities	391,628	381,366
PSNH | EDIT due to Tax Cuts and Jobs Act of 2017
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	348,600	359,200
PSNH | Cost of Removal
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	14,700	17,200
PSNH | Regulatory Tracking Mechanisms
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	155,000	107,000
PSNH | Deferred Portion of Non-Service Income Components of Pension, SERP and PBOP
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	28,800	14,900
PSNH | Benefit Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
PSNH | AFUDC - Transmission
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
PSNH | CL&P Settlement Agreement and Storm Performance Penalty
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
PSNH | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 6,500	$ 3,300

PROPERTY, PLANT AND EQUIPMENT_3

PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Investment in Utility Property, Plant and Equipment By Asset (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Distribution - Electric	$ 18,326,200	$ 17,679,100
Distribution - Natural Gas	7,443,800	6,694,800
Transmission - Electric	13,709,300	12,882,400
Distribution - Water	2,112,600	1,900,900
Solar	200,800	200,900
Utility	41,792,700	39,358,100
Other	1,738,100	1,469,500
Property, Plant and Equipment, Gross	43,530,800	40,827,600
Less:  Accumulated Depreciation
Utility	(9,167,400)	(8,885,200)
Other	(706,100)	(580,100)
Total Accumulated Depreciation	(9,873,500)	(9,465,300)
Property, Plant and Equipment, Net	33,657,300	31,362,300
Construction Work in Progress	2,455,500	2,015,400
Total Property, Plant and Equipment, Net	36,112,820	33,377,650
CL&P
Property, Plant and Equipment [Line Items]
Distribution - Electric	7,370,100	7,117,600
Transmission - Electric	6,165,100	5,859,000
Solar	0	0
Property, Plant and Equipment, Gross	13,535,200	12,976,600
Less:  Accumulated Depreciation
Total Accumulated Depreciation	(2,567,100)	(2,572,100)
Property, Plant and Equipment, Net	10,968,100	10,404,500
Construction Work in Progress	498,900	399,000
Total Property, Plant and Equipment, Net	11,467,024	10,803,543
NSTAR Electric
Property, Plant and Equipment [Line Items]
Distribution - Electric	8,410,000	8,105,500
Transmission - Electric	5,333,800	5,090,500
Solar	200,800	200,900
Property, Plant and Equipment, Gross	13,944,600	13,396,900
Less:  Accumulated Depreciation
Total Accumulated Depreciation	(3,381,200)	(3,227,300)
Property, Plant and Equipment, Net	10,563,400	10,169,600
Construction Work in Progress	1,063,600	707,000
Total Property, Plant and Equipment, Net	11,626,968	10,876,614
PSNH
Property, Plant and Equipment [Line Items]
Distribution - Electric	2,586,400	2,496,200
Transmission - Electric	2,212,000	1,934,600
Solar	0	0
Property, Plant and Equipment, Gross	4,798,400	4,430,800
Less:  Accumulated Depreciation
Total Accumulated Depreciation	(912,300)	(908,400)
Property, Plant and Equipment, Net	3,886,100	3,522,400
Construction Work in Progress	174,100	134,100
Total Property, Plant and Equipment, Net	$ 4,060,224	$ 3,656,462

PROPERTY, PLANT AND EQUIPMENT_4

PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Schedule of Aggregate Composite Depreciation Rates (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Composite depreciation rate for plant in service (in percent)	3%	3.10%	3%
CL&P
Property, Plant and Equipment [Line Items]
Composite depreciation rate for plant in service (in percent)	2.80%	2.80%	2.80%
NSTAR Electric
Property, Plant and Equipment [Line Items]
Composite depreciation rate for plant in service (in percent)	2.70%	2.80%	2.80%
PSNH
Property, Plant and Equipment [Line Items]
Composite depreciation rate for plant in service (in percent)	3%	3.10%	2.80%

PROPERTY, PLANT AND EQUIPMENT_5

PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Schedule of Average Remaining Useful Lives of Depreciable Assets (Details)	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Distribution - Electric	34 years 2 months 12 days
Distribution - Natural Gas	37 years 4 months 24 days
Transmission - Electric	39 years 9 months 18 days
Distribution - Water	39 years
Solar	22 years 10 months 24 days
Other	11 years
Computer Software, Hardware and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of property, plant and equipment	5 years
Computer Software, Hardware and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of property, plant and equipment	15 years
Buildings
Property, Plant and Equipment [Line Items]
Estimated useful life of property, plant and equipment	40 years
CL&P
Property, Plant and Equipment [Line Items]
Distribution - Electric	35 years
Transmission - Electric	36 years 3 months 18 days
NSTAR Electric
Property, Plant and Equipment [Line Items]
Distribution - Electric	34 years 7 months 6 days
Transmission - Electric	45 years 2 months 12 days
Solar	22 years 10 months 24 days
PSNH
Property, Plant and Equipment [Line Items]
Distribution - Electric	30 years 9 months 18 days
Transmission - Electric	39 years 3 months 18 days

DERIVATIVE INSTRUMENTS - Schedu

DERIVATIVE INSTRUMENTS - Schedule of Gross Fair Value of Contracts (Details) - CL&P - Level 3 - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Current Derivative Assets
Current and Long-Term Derivative Assets
Commodity Supply and Price Risk Management	$ 16.3	$ 14.7
Netting	(0.5)	(1)
Net Amount Recorded as a Derivative	15.8	13.7
Long-Term Derivative Assets
Current and Long-Term Derivative Assets
Commodity Supply and Price Risk Management	28.8	46.9
Netting	(0.9)	(0.9)
Net Amount Recorded as a Derivative	27.9	46
Current Derivative Liabilities
Current and Long-Term Derivative Liabilities
Commodity Supply and Price Risk Management	(81.6)	(73.5)
Netting	0	0
Net Amount Recorded as a Derivative	(81.6)	(73.5)
Long-Term Derivative Liabilities
Current and Long-Term Derivative Liabilities
Commodity Supply and Price Risk Management	(143.9)	(235.4)
Netting	0	0
Net Amount Recorded as a Derivative	$ (143.9)	$ (235.4)

DERIVATIVE INSTRUMENTS - Narrat

DERIVATIVE INSTRUMENTS - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) MW	Dec. 31, 2021 USD ($) $ / KWmo MW	Dec. 31, 2020 USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Percentage of costs or benefits borne under capacity-related contracts by United Illuminated Company (as a percentage)	20%
Amount of power to be purchased under capacity-related contract (up to) (in MW) | MW	674	675
Gain (loss) on deferred regulatory costs | $	$ 10.1	$ (7.1)	$ (21.2)
CL&P
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Percentage of costs or benefits borne under capacity-related contracts (as a percentage)	80%
Minimum | Level 3
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Percentage of exit price premiums related to derivative contracts	2.90%
Average | CL&P | Measurement Input, Capacity Prices
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative measurement input | $ / KWmo		2.61
Average | Level 3
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Percentage of exit price premiums related to derivative contracts	6.10%
Maximum | Level 3
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Percentage of exit price premiums related to derivative contracts	7.10%

DERIVATIVE INSTRUMENTS - Unobse

DERIVATIVE INSTRUMENTS - Unobservable Inputs Utilized (Details) - Forward Reserve Prices - CL&P - Level 3 - $ / KWmo	Dec. 31, 2022	Dec. 31, 2021
Minimum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative measurement input	0.44	0.50
Maximum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative measurement input	0.50	1.15
Average
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative measurement input	0.47	0.82

DERIVATIVE INSTRUMENTS - Variat

DERIVATIVE INSTRUMENTS - Variations Using Significant unobservable Inputs (Details) - Level 3 - CL&P - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value as of Beginning of Period	$ (249.2)	$ (293.1)
Net Realized/Unrealized Gains/(Losses) Included in Regulatory Assets	10.1	(8.5)
Settlements	57.3	52.4
Fair Value as of End of Period	$ (181.8)	$ (249.2)

MARKETABLE SECURITIES - Narrati

MARKETABLE SECURITIES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 20	$ 40.2
Unrealized losses recorded in other income	9.7
Unrealized gains recorded in other income		4.4	$ 3.7
CYAPC and YAEC
Debt Securities, Available-for-sale [Line Items]
Equity securities	170.1	214
Marketable securities held in nuclear decommissioning trusts	$ 163.2	$ 189.9

MARKETABLE SECURITIES - Availab

MARKETABLE SECURITIES - Available-for-Sale Debt Securities (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Amortized Cost	$ 201.6	$ 214.5
Pre-Tax Unrealized Gains	0.1	5.1
Pre-Tax Unrealized Losses	(16.2)	(0.2)
Fair Value	$ 185.5	$ 219.4

MARKETABLE SECURITIES - Contrac

MARKETABLE SECURITIES - Contractual Maturity (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Amortized Cost
Less than one year	$ 28.5
One to five years	43.8
Six to ten years	35.6
Greater than ten years	93.7
Amortized Cost	201.6	$ 214.5
Fair Value
Less than one year	28.3
One to five years	42.4
Six to ten years	32.3
Greater than ten years	82.5
Total Debt Securities	$ 185.5	$ 219.4

MARKETABLE SECURITIES - Fair Va

MARKETABLE SECURITIES - Fair Value Measurement (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	$ 375.6	$ 473.6
Level 1
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	215.5	285.5
Level 1 | Mutual Funds and Equities
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	190.1	254.2
Level 1 | Money Market Funds
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	25.4	31.3
Level 2
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	160.1	188.1
Level 2 | U.S. Government Issued Debt Securities (Agency and Treasury)
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	82.3	81.3
Level 2 | Corporate Debt Securities
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	46.1	65.3
Level 2 | Asset-Backed Debt Securities
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	8.6	12.6
Level 2 | Municipal Bonds
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	12.7	12.3
Level 2 | Other Fixed Income Securities
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	$ 10.4	$ 16.6

INVESTMENTS IN UNCONSOLIDATED_3

INVESTMENTS IN UNCONSOLIDATED AFFILIATES - Summary of Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated affiliates	$ 2,176,080	$ 1,436,293
Offshore Wind Business - North East Offshore
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)	50%
Investments in unconsolidated affiliates	$ 1,947,100	1,213,600
Natural Gas Pipeline - Algonquin Gas Transmission, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)	15%
Investments in unconsolidated affiliates	$ 118,800	121,900
Renewable Energy Investment Fund
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)	90%
Investments in unconsolidated affiliates	$ 84,100	76,500
Other
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated affiliates	$ 26,100	$ 24,300

INVESTMENTS IN UNCONSOLIDATED_4

INVESTMENTS IN UNCONSOLIDATED AFFILIATES - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) company project	Dec. 31, 2021 USD ($) company	Dec. 31, 2020 USD ($)
Schedule of Equity Method Investments [Line Items]
Equity in earnings of unconsolidated affiliates, net of impairment	$ 22,900	$ 14,200	$ 14,200
Dividends received from equity method investees	$ 26,200	$ 21,600	21,800
Number of offshore wind projects | project	3
Number of companies that transmit hydro electricity imported from The Hydro-Quebec System in Canada | company	2	2
Payments to acquire investments	$ 742,496	$ 327,385	239,673
Offshore Wind Business - North East Offshore
Schedule of Equity Method Investments [Line Items]
Carrying amount of equity method investments in excess of the underlying equity in net assets	343,100	$ 300,400
Goodwill	$ 168,900
Ownership interest (in percent)	50%
Revolution Wind And South Fork Wind
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)	50%
Hydro-Quebec System
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)	14.50%	14.50%
Payments to acquire investments	$ 9,300	$ 9,000
Renewable Energy Fund
Schedule of Equity Method Investments [Line Items]
Other-than-temporary impairment		$ 2,800	$ 2,800

ASSET RETIREMENT OBLIGATIONS -

ASSET RETIREMENT OBLIGATIONS - Schedule of Reconciliation of Beginning and Ending Balance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of Beginning of Year	$ 500.1	$ 499.7
Liabilities Settled During the Year	(22.3)	(23.9)
Accretion	28.9	29.4
Revisions in Estimated Cash Flows	(4)	(5.1)
Balance as of End of Year	502.7	500.1
CL&P
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of Beginning of Year	35	33.4
Liabilities Settled During the Year	0	(0.6)
Accretion	2.4	2.2
Revisions in Estimated Cash Flows	0	0
Balance as of End of Year	37.4	35
NSTAR Electric
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of Beginning of Year	97.5	91.8
Liabilities Settled During the Year	0	0
Accretion	4.1	4
Revisions in Estimated Cash Flows	(0.3)	1.7
Balance as of End of Year	101.3	97.5
PSNH
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of Beginning of Year	4.7	4.4
Liabilities Settled During the Year	0	0
Accretion	0.2	0.3
Revisions in Estimated Cash Flows	0	0
Balance as of End of Year	$ 4.9	$ 4.7

ASSET RETIREMENT OBLIGATIONS _2

ASSET RETIREMENT OBLIGATIONS - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule of Asset Retirement Obligation [Line Items]
Asset retirement obligations	$ 502.7	$ 500.1	$ 499.7
CYAPC and YAEC
Schedule of Asset Retirement Obligation [Line Items]
Asset retirement obligations	$ 320.5	$ 325.9

SHORT-TERM DEBT - Narrative (De

SHORT-TERM DEBT - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 03, 2021
Commercial Paper | Eversource
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 2,000,000,000
Line of Credit
Short-term Debt [Line Items]
Amount outstanding during period	0	$ 0
Line of Credit | Eversource
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 2,000,000,000
Debt instrument term (in years)	5 years
CL&P
Short-term Debt [Line Items]
Short-term borrowing limit approved by regulatory agency			$ 600,000,000
CL&P | Unsecured Debt
Short-term Debt [Line Items]
Period of maturity restricting provisions of debt	10 years
Total capitalization (as a percentage)	10%
Capacity available under preferred stock provisions	$ 1,010,000,000
CL&P | Line of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity	450,000,000
Borrowings outstanding	0
NSTAR Electric
Short-term Debt [Line Items]
Short-term borrowing limit approved by regulatory agency			$ 655,000,000
NSTAR Electric | Commercial Paper
Short-term Debt [Line Items]
Maximum borrowing capacity	650,000,000
NSTAR Electric | Line of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 650,000,000
Debt instrument term (in years)	5 years
PSNH
Short-term Debt [Line Items]
Short-term borrowing limit approved by regulatory agency	$ 443,500,000
Notes payable to related parties	$ 173,300,000	$ 110,600,000
PSNH | Short Term Debt Authorization Calculation
Short-term Debt [Line Items]
Interest rate	10%
Short-term debt borrowing calculation approved by regulatory agency	$ 60,000,000
PSNH | Line of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 300,000,000

SHORT-TERM DEBT - Schedule of D

SHORT-TERM DEBT - Schedule of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Line of Credit Facility [Line Items]
Borrowings Outstanding	$ 1,442,200	$ 1,505,450
Eversource Parent Commercial Paper Program
Line of Credit Facility [Line Items]
Borrowings Outstanding	1,442,200	1,342,950
Commercial Paper | Eversource Parent Commercial Paper Program
Line of Credit Facility [Line Items]
Borrowings Outstanding	1,442,200	1,343,000
Available Borrowing Capacity	$ 557,800	$ 657,000
Weighted-Average Interest Rate (as a percentage)	4.63%	0.31%
Commercial Paper | NSTAR Electric
Line of Credit Facility [Line Items]
Borrowings Outstanding	$ 0	$ 162,500
Available Borrowing Capacity	$ 650,000	$ 487,500
Weighted-Average Interest Rate (as a percentage)	0%	0.14%

LONG-TERM DEBT - Schedule of Lo

LONG-TERM DEBT - Schedule of Long-Term Debt Outstanding (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Long-Term Debt	$ 19,723,994	$ 17,023,577
Long-Term Debt – Current Portion	1,320,129	1,193,097
Senior Notes
Debt Instrument [Line Items]
Unamortized Premiums and Discounts, Net	40,100	43,400
Unamortized Debt Issuance Costs	(49,400)	(36,300)
Long-Term Debt	19,724,000	17,023,600
Pre-1983 Spent Nuclear Fuel Obligation (CYAPC)
Debt Instrument [Line Items]
Long-Term Debt	11,900	11,700
Fair Value Adjustment
Debt Instrument [Line Items]
Long-Term Debt	26,200	43,800
Fair Value Adjustment - Current Portion
Debt Instrument [Line Items]
Long-Term Debt	(7,000)	(17,700)
Loans Payable
Debt Instrument [Line Items]
Long-Term Debt – Current Portion	1,203,400	775,400
Total Other Long-Term Debt
Debt Instrument [Line Items]
Long-Term Debt	10,027,500	8,059,000
Eversource
Debt Instrument [Line Items]
Long-Term Debt	6,972,804	5,395,840
Long-Term Debt – Current Portion	1,207,047	767,681
Eversource | Unsecured Debt | Eversource Parent - Senior Notes due 2023 - 2050
Debt Instrument [Line Items]
Long-Term Debt	$ 8,150,000	6,100,000
Eversource | Unsecured Debt | Eversource Parent - Senior Notes due 2023 - 2050 | Minimum
Debt Instrument [Line Items]
Interest rate	0.80%
Eversource | Unsecured Debt | Eversource Parent - Senior Notes due 2023 - 2050 | Maximum
Debt Instrument [Line Items]
Interest rate	4.60%
CL&P
Debt Instrument [Line Items]
Long-Term Debt	$ 4,216,488	4,215,379
Long-Term Debt – Current Portion	400,000	0
CL&P | First Mortgage Bonds
Debt Instrument [Line Items]
Long-Term Debt	4,219,800	4,219,800
Unamortized Premiums and Discounts, Net	21,500	23,100
Unamortized Debt Issuance Costs	(24,800)	(27,500)
Long-Term Debt	$ 4,216,500	4,215,400
CL&P | First Mortgage Bonds | 1994 Series D due 2024
Debt Instrument [Line Items]
Interest rate	7.875%
Long-Term Debt	$ 139,800	139,800
CL&P | First Mortgage Bonds | 2004 Series B due 2034
Debt Instrument [Line Items]
Interest rate	5.75%
Long-Term Debt	$ 130,000	130,000
CL&P | First Mortgage Bonds | 2005 Series B due 2035
Debt Instrument [Line Items]
Interest rate	5.625%
Long-Term Debt	$ 100,000	100,000
CL&P | First Mortgage Bonds | 2006 Series A due 2036
Debt Instrument [Line Items]
Interest rate	6.35%
Long-Term Debt	$ 250,000	250,000
CL&P | First Mortgage Bonds | 2007 Series B due 2037
Debt Instrument [Line Items]
Interest rate	5.75%
Long-Term Debt	$ 150,000	150,000
CL&P | First Mortgage Bonds | 2007 Series D due 2037
Debt Instrument [Line Items]
Interest rate	6.375%
Long-Term Debt	$ 100,000	100,000
CL&P | First Mortgage Bonds | 2013 Series A due 2023
Debt Instrument [Line Items]
Interest rate	2.50%
Long-Term Debt	$ 400,000	400,000
CL&P | First Mortgage Bonds | 2014 Series A due 2044
Debt Instrument [Line Items]
Interest rate	4.30%
Long-Term Debt	$ 475,000	475,000
CL&P | First Mortgage Bonds | 2015 Series A due 2045
Debt Instrument [Line Items]
Interest rate	4.15%
Long-Term Debt	$ 350,000	350,000
CL&P | First Mortgage Bonds | 2017 Series A due 2027
Debt Instrument [Line Items]
Interest rate	3.20%
Long-Term Debt	$ 500,000	500,000
CL&P | First Mortgage Bonds | 2018 Series A due 2048
Debt Instrument [Line Items]
Interest rate	4%
Long-Term Debt	$ 800,000	800,000
CL&P | First Mortgage Bonds | 2020 Series A due 2025
Debt Instrument [Line Items]
Interest rate	0.75%
Long-Term Debt	$ 400,000	400,000
CL&P | First Mortgage Bonds | 2021 Series A due 2031
Debt Instrument [Line Items]
Interest rate	2.05%
Long-Term Debt	$ 425,000	425,000
CL&P | Commercial Paper
Debt Instrument [Line Items]
Long-Term Debt	400,000
Long-Term Debt – Current Portion	400,000	0
NSTAR Electric
Debt Instrument [Line Items]
Long-Term Debt	4,345,085	3,585,399
Long-Term Debt – Current Portion	80,000	400,000
NSTAR Electric | Unsecured Debt
Debt Instrument [Line Items]
Long-Term Debt	4,250,000	3,800,000
Long-Term Debt – Current Portion	80,000	400,000
Unamortized Premiums and Discounts, Net	(14,800)	(11,200)
Unamortized Debt Issuance Costs	(30,100)	(23,400)
Long-Term Debt	$ 4,345,100	3,585,400
NSTAR Electric | Unsecured Debt | 2006 Debentures due 2036
Debt Instrument [Line Items]
Interest rate	5.75%
Long-Term Debt	$ 200,000	200,000
NSTAR Electric | Unsecured Debt | 2010 Debentures due 2040
Debt Instrument [Line Items]
Interest rate	5.50%
Long-Term Debt	$ 300,000	300,000
NSTAR Electric | Unsecured Debt | 2012 Debentures due 2022
Debt Instrument [Line Items]
Interest rate	2.375%
Long-Term Debt	$ 0	400,000
NSTAR Electric | Unsecured Debt | 2014 Debentures due 2044
Debt Instrument [Line Items]
Interest rate	4.40%
Long-Term Debt	$ 300,000	300,000
NSTAR Electric | Unsecured Debt | 2015 Debentures due 2025
Debt Instrument [Line Items]
Interest rate	3.25%
Long-Term Debt	$ 250,000	250,000
NSTAR Electric | Unsecured Debt | 2016 Debentures due 2026
Debt Instrument [Line Items]
Interest rate	2.70%
Long-Term Debt	$ 250,000	250,000
NSTAR Electric | Unsecured Debt | 2017 Debentures due 2027
Debt Instrument [Line Items]
Interest rate	3.20%
Long-Term Debt	$ 700,000	700,000
NSTAR Electric | Unsecured Debt | 2019 Debentures due 2029
Debt Instrument [Line Items]
Interest rate	3.25%
Long-Term Debt	$ 400,000	400,000
NSTAR Electric | Unsecured Debt | 2020 Debentures due 2030
Debt Instrument [Line Items]
Interest rate	3.95%
Long-Term Debt	$ 400,000	400,000
NSTAR Electric | Unsecured Debt | 2021 Debentures due 2051
Debt Instrument [Line Items]
Interest rate	3.10%
Long-Term Debt	$ 300,000	300,000
NSTAR Electric | Unsecured Debt | 2021 Debentures due 2031
Debt Instrument [Line Items]
Interest rate	1.95%
Long-Term Debt	$ 300,000	300,000
NSTAR Electric | Unsecured Debt | 2022 Debentures due 2052
Debt Instrument [Line Items]
Interest rate	4.55%
Long-Term Debt	$ 450,000	0
NSTAR Electric | Unsecured Debt | 2022 Debentures due 2052
Debt Instrument [Line Items]
Interest rate	4.95%
Long-Term Debt	$ 400,000	0
NSTAR Electric | Senior Notes
Debt Instrument [Line Items]
Long-Term Debt	$ 220,000	220,000
NSTAR Electric | Senior Notes | 2004 Senior Notes Series B due 2034
Debt Instrument [Line Items]
Interest rate	5.90%
Long-Term Debt	$ 50,000	50,000
NSTAR Electric | Senior Notes | 2007 Senior Notes Series D due 2037
Debt Instrument [Line Items]
Interest rate	6.70%
Long-Term Debt	$ 40,000	40,000
NSTAR Electric | Senior Notes | 2013 Senior Notes Series G due 2023
Debt Instrument [Line Items]
Interest rate	3.88%
Long-Term Debt	$ 80,000	80,000
NSTAR Electric | Senior Notes | 2016 Senior Notes Series H due 2026
Debt Instrument [Line Items]
Interest rate	2.75%
Long-Term Debt	$ 50,000	50,000
PSNH
Debt Instrument [Line Items]
Long-Term Debt	1,134,914	1,163,833
Long-Term Debt – Current Portion	29,668	0
PSNH | First Mortgage Bonds
Debt Instrument [Line Items]
Long-Term Debt	1,175,000	1,175,000
Long-Term Debt – Current Portion	325,000	0
Unamortized Premiums and Discounts, Net	(2,500)	(2,600)
Unamortized Debt Issuance Costs	(7,900)	(8,600)
Long-Term Debt	$ 1,134,900	1,163,800
PSNH | First Mortgage Bonds | 2005 Series M due 2035
Debt Instrument [Line Items]
Interest rate	5.60%
Long-Term Debt	$ 50,000	50,000
PSNH | First Mortgage Bonds | 2013 Series S due 2023
Debt Instrument [Line Items]
Interest rate	3.50%
Long-Term Debt	$ 325,000	325,000
PSNH | First Mortgage Bonds | 2019 Series T due 2049
Debt Instrument [Line Items]
Interest rate	3.60%
Long-Term Debt	$ 300,000	300,000
PSNH | First Mortgage Bonds | 2020 Series U due 2050
Debt Instrument [Line Items]
Interest rate	2.40%
Long-Term Debt	$ 150,000	150,000
PSNH | First Mortgage Bonds | 2021 Series V due 2031
Debt Instrument [Line Items]
Interest rate	2.20%
Long-Term Debt	$ 350,000	350,000
PSNH | Commercial Paper
Debt Instrument [Line Items]
Long-Term Debt	295,300
Long-Term Debt – Current Portion	295,300	0
Yankee Gas | First Mortgage Bonds | Yankee Gas - First Mortgage Bonds due 2024 - 2051
Debt Instrument [Line Items]
Long-Term Debt	$ 845,000	765,000
Yankee Gas | First Mortgage Bonds | Yankee Gas - First Mortgage Bonds due 2024 - 2051 | Minimum
Debt Instrument [Line Items]
Interest rate	1.38%
Yankee Gas | First Mortgage Bonds | Yankee Gas - First Mortgage Bonds due 2024 - 2051 | Maximum
Debt Instrument [Line Items]
Interest rate	5.35%
NSTAR Gas | First Mortgage Bonds | NSTAR Gas - First Mortgage Bonds due 2025 - 2051
Debt Instrument [Line Items]
Long-Term Debt	$ 705,000	580,000
NSTAR Gas | First Mortgage Bonds | NSTAR Gas - First Mortgage Bonds due 2025 - 2051 | Minimum
Debt Instrument [Line Items]
Interest rate	2.25%
NSTAR Gas | First Mortgage Bonds | NSTAR Gas - First Mortgage Bonds due 2025 - 2051 | Maximum
Debt Instrument [Line Items]
Interest rate	7.11%
EGMA | First Mortgage Bonds | EGMA - First Mortgage Bonds due 2031 - 2052
Debt Instrument [Line Items]
Long-Term Debt	$ 650,000	550,000
EGMA | First Mortgage Bonds | EGMA - First Mortgage Bonds due 2031 - 2052 | Minimum
Debt Instrument [Line Items]
Interest rate	2.11%
EGMA | First Mortgage Bonds | EGMA - First Mortgage Bonds due 2031 - 2052 | Maximum
Debt Instrument [Line Items]
Interest rate	4.70%
Aquarion | Unsecured Debt | Aquarion - Unsecured Notes due 2023 - 2052
Debt Instrument [Line Items]
Long-Term Debt	$ 464,700	394,900
Aquarion | Unsecured Debt | Aquarion - Unsecured Notes due 2023 - 2052 | Minimum
Debt Instrument [Line Items]
Interest rate	0%
Aquarion | Unsecured Debt | Aquarion - Unsecured Notes due 2023 - 2052 | Maximum
Debt Instrument [Line Items]
Interest rate	6.43%
Aquarion | Secured Debt | Aquarion - Secured Debt due 2023 - 2044
Debt Instrument [Line Items]
Long-Term Debt	$ 34,400	39,600
Aquarion | Secured Debt | Aquarion - Secured Debt due 2023 - 2044 | Minimum
Debt Instrument [Line Items]
Interest rate	2.864%
Aquarion | Secured Debt | Aquarion - Secured Debt due 2023 - 2044 | Maximum
Debt Instrument [Line Items]
Interest rate	9.29%
Aquarion | Senior Notes | Aquarion - Senior Notes due 2024
Debt Instrument [Line Items]
Interest rate	4%
Long-Term Debt	$ 360,000	$ 360,000

LONG-TERM DEBT - Schedule of Is

LONG-TERM DEBT - Schedule of Issuances and Repayments (Details) - USD ($) $ in Thousands

1 Months Ended

12 Months Ended

Jan. 31, 2023

Oct. 31, 2022

Sep. 30, 2022

Aug. 31, 2022

Jul. 31, 2022

Jun. 30, 2022

May 31, 2022

Mar. 31, 2022

Feb. 28, 2022

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2020

Debt Instrument [Line Items]

Repayments of debt

$ (1,175,000)

$ (1,142,500)

$ (327,236)

NSTAR Electric

Debt Instrument [Line Items]

Repayments of debt

(400,000)

(250,000)

(95,000)

CL&P

Debt Instrument [Line Items]

Repayments of debt

0

(120,500)

0

PSNH

Debt Instrument [Line Items]

Repayments of debt

0

(282,000)

0

CL&P 2023 Series A First Mortgage Bonds | Mortgage Bonds | CL&P | Subsequent Event

Debt Instrument [Line Items]

Interest rate

5.25%

Issuance

$ 500,000

CL&P 2013 Series A First Mortgage Bonds | Mortgage Bonds | CL&P | Subsequent Event

Debt Instrument [Line Items]

Interest rate

2.50%

Repayments of debt

$ (400,000)

NSTAR Electric 2022 Debentures | Debentures | NSTAR Electric

Debt Instrument [Line Items]

Interest rate

4.55%

Issuance

$ 450,000

NSTAR Electric 2022 Debentures | Debentures | NSTAR Electric

Debt Instrument [Line Items]

Interest rate

4.95%

Issuance

$ 400,000

NSTAR Electric 2012 Debentures | Debentures | NSTAR Electric

Debt Instrument [Line Items]

Interest rate

2.375%

Repayments of debt

$ (400,000)

PSNH Series W First Mortgage Bonds | Mortgage Bonds | PSNH | Subsequent Event

Debt Instrument [Line Items]

Interest rate

5.15%

Issuance

$ 300,000

Yankee Gas Series B First Mortgage Bonds | First Mortgage Bonds | Yankee Gas Services Company

Debt Instrument [Line Items]

Interest rate

8.48%

Repayments of debt

$ (20,000)

Yankee Gas Series U First Mortgage Bonds | First Mortgage Bonds | Yankee Gas Services Company

Debt Instrument [Line Items]

Interest rate

4.31%

Issuance

$ 100,000

EGMA Series C First Mortgage Bonds | First Mortgage Bonds | EGMA

Debt Instrument [Line Items]

Interest rate

4.70%

Issuance

$ 100,000

NSTAR Gas Series V First Mortgage Bonds | First Mortgage Bonds | NSTAR Gas

Debt Instrument [Line Items]

Interest rate

4.40%

Issuance

$ 125,000

Aquarion Water Company of New Hampshire General Mortgage Bonds | General Mortgage Bonds (GMB) | Aquarion Water Company

Debt Instrument [Line Items]

Interest rate

4.45%

Repayments of debt

$ (5,000)

Aquarion Water Company of Connecticut Senior Notes | Senior Notes | Aquarion Water Company

Debt Instrument [Line Items]

Interest rate

4.69%

Issuance

$ 70,000

Eversource

Debt Instrument [Line Items]

Repayments of debt

$ (750,000)

$ (450,000)

$ 0

Eversource | Eversource Parent Series V Senior Notes | Senior Notes

Debt Instrument [Line Items]

Interest rate

2.90%

Issuance

$ 650,000

Eversource | Eversource Parent Series W Senior Notes | Senior Notes

Debt Instrument [Line Items]

Interest rate

3.375%

Issuance

$ 650,000

Eversource | Eversource Parent Series X Senior Notes | Senior Notes

Debt Instrument [Line Items]

Interest rate

4.20%

Issuance

$ 900,000

Eversource | Eversource Parent Series Y Senior Notes | Senior Notes

Debt Instrument [Line Items]

Interest rate

4.60%

Issuance

$ 600,000

Eversource | Eversource Parent Series K Senior Notes | Senior Notes

Debt Instrument [Line Items]

Interest rate

2.75%

Repayments of debt

$ (750,000)

LONG-TERM DEBT - Narrative (Det

LONG-TERM DEBT - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 14, 2022	Nov. 30, 2022	Jun. 14, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Long-term debt	$ 19,723,994				$ 17,023,577
Interest included in payment to settle spent nuclear fuel obligation	8,800				8,700
CL&P
Debt Instrument [Line Items]
Long-term debt	4,216,488				4,215,379
PSNH
Debt Instrument [Line Items]
Long-term debt	1,134,914				1,163,833
Line of Credit | NSTAR Gas
Debt Instrument [Line Items]
Amount of long-term debt requested for issuance				$ 325,000
Line of Credit | CL&P
Debt Instrument [Line Items]
Amount of long-term debt requested for issuance			$ 1,150,000
Line of Credit | PSNH
Debt Instrument [Line Items]
Amount of long-term debt requested for issuance		$ 600,000
Pre-1983 Spent Nuclear Fuel Obligation (CYAPC)
Debt Instrument [Line Items]
Long-term debt	$ 11,900				$ 11,700

LONG-TERM DEBT - Schedule of _2

LONG-TERM DEBT - Schedule of Long-term Debt Maturities (Details) $ in Millions	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
2023	$ 2,008.4
2024	1,950
2025	1,400.2
2026	940.2
2027	2,539.2
Thereafter	12,236
Total	21,074
CL&P
Debt Instrument [Line Items]
2023	400
2024	139.8
2025	400
2026	0
2027	500
Thereafter	2,780
Total	4,219.8
NSTAR Electric
Debt Instrument [Line Items]
2023	80
2024	0
2025	250
2026	300
2027	700
Thereafter	3,140
Total	4,470
PSNH
Debt Instrument [Line Items]
2023	325
2024	0
2025	0
2026	0
2027	0
Thereafter	850
Total	$ 1,175

RATE REDUCTION BONDS AND VARI_3

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Narrative (Details) - PSNH - Rate Reduction Bonds - USD ($) $ in Millions	May 31, 2018	May 08, 2018
Debt Instrument [Line Items]
Amount of securitized rate reduction bonds issued	$ 635.7
Weighted average interest rate (in percent)		3.66%

RATE REDUCTION BONDS AND VARI_4

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	$ 5,578,300	$ 5,715,800
Regulatory Liabilities	3,930,305	3,866,251
Accrued Interest (included in Other Current Liabilities)	989,053	830,620
Rate Reduction Bonds - Current Portion	43,210	43,210
Rate Reduction Bonds - Long-Term Portion	410,492	453,702
Other Long-Term Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Restricted Cash	$ 19,600	$ 44,700
Restricted Cash and Cash Equivalents, Statement of Financial Position [Extensible Enumeration]	Other Long-Term Assets	Other Long-Term Assets
Other Current Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Restricted Cash and Cash Equivalents, Statement of Financial Position [Extensible Enumeration]	Prepayments and Other Current Assets	Prepayments and Other Current Assets
Securitized Stranded Costs
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	$ 435,700	$ 478,900
Other Regulatory Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	322,500	150,000
PSNH
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	696,200	786,400
Regulatory Liabilities	391,628	381,366
Accrued Interest (included in Other Current Liabilities)	59,616	63,005
Rate Reduction Bonds - Current Portion	43,210	43,210
Rate Reduction Bonds - Long-Term Portion	410,492	453,702
PSNH | Other Long-Term Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Restricted Cash	3,200	3,200
PSNH | Securitized Stranded Costs
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	435,700	478,900
PSNH | Other Regulatory Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	14,400	15,800
Variable Interest Entity, Primary Beneficiary | PSNH
Condensed Balance Sheet Statements, Captions [Line Items]
Rate Reduction Bonds - Current Portion	43,200	43,200
Rate Reduction Bonds - Long-Term Portion	410,500	453,700
Variable Interest Entity, Primary Beneficiary | PSNH | Other Long-Term Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Restricted Cash	3,200	3,200
Variable Interest Entity, Primary Beneficiary | PSNH | Other Current Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Restricted Cash	32,400	31,100
Variable Interest Entity, Primary Beneficiary | PSNH | Securitized Stranded Costs
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	435,700	478,900
Variable Interest Entity, Primary Beneficiary | PSNH | Other Regulatory Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Regulatory Liabilities	6,000	5,400
Accrued Interest (included in Other Current Liabilities)	$ 6,900	$ 7,500

RATE REDUCTION BONDS AND VARI_5

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Income Statement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Income Statements, Captions [Line Items]
Interest Expense on RRB Principal (included in Interest Expense)	$ 678,274	$ 582,334	$ 538,452
PSNH
Condensed Income Statements, Captions [Line Items]
Amortization of RRB Principal (included in Amortization of Regulatory Assets, Net)	42,867	86,832	52,804
Interest Expense on RRB Principal (included in Interest Expense)	59,548	56,998	58,127
Variable Interest Entity, Primary Beneficiary | PSNH | Rate Reduction Bonds
Condensed Income Statements, Captions [Line Items]
Amortization of RRB Principal (included in Amortization of Regulatory Assets, Net)	43,200	43,200	43,200
Interest Expense on RRB Principal (included in Interest Expense)	$ 17,000	$ 18,400	$ 19,700

RATE REDUCTION BONDS AND VARI_6

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES- Rate Reduction Bonds, Principal and Interest Payments (Details) - PSNH $ in Millions	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
2023	$ 43.2
2024	43.2
2025	43.2
2026	43.2
2027	43.2
Thereafter	237.7
Total	$ 453.7

EMPLOYEE BENEFITS - Schedule of

EMPLOYEE BENEFITS - Schedule of Pension Benefit Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension and SERP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	$ (6,729.7)	$ (7,045.3)
Service Cost	(70.1)	(85.8)	$ (76.2)
Interest Cost	(154.5)	(130)	(177.8)
Actuarial Gain	1,385.8	177.1
Benefits Paid	302.5	309.5
Benefits Paid - Lump Sum	33	34.7
Benefits Paid - SERP	12.9	10.1
Employee Transfers	0	0
Benefit Obligation as of End of Year	(5,220.1)	(6,729.7)	(7,045.3)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	6,495.5	5,409.2
Actual Return on Plan Assets	(433.6)	1,250.5
Employer Contributions	80	180
Benefits Paid - Pension	(302.5)	(309.5)
Benefits Paid - Lump Sum	(33)	(34.7)
Employee Transfers	0	0
Fair Value of Plan Assets as of End of Year	5,806.4	6,495.5	5,409.2
Funded Status as of December 31st	586.3	(234.2)
PBOP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(884.3)	(993.9)
Service Cost	(11.6)	(13.5)	(10.2)
Interest Cost	(20.2)	(17.4)	(24.6)
Actuarial Gain	173.6	81.4
Benefits Paid	52.1	51.7
Employee Transfers	0	0
Impact of Acquisitions	(3.3)	7.4
Benefit Obligation as of End of Year	(693.7)	(884.3)	(993.9)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	1,138.3	1,004.1
Actual Return on Plan Assets	(119.6)	183.2
Employer Contributions	3.1	2.3
Benefits Paid - Pension	(51.7)	(51.3)
Employee Transfers	0	0
Fair Value of Plan Assets as of End of Year	970.1	1,138.3	1,004.1
Funded Status as of December 31st	276.4	254
CL&P | Pension and SERP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(1,330.9)	(1,477.3)
Service Cost	(18.7)	(23)	(21.8)
Interest Cost	(31.3)	(27.3)	(37.3)
Actuarial Gain	284.1	127.8
Benefits Paid	63.3	64.6
Benefits Paid - Lump Sum	0	0
Benefits Paid - SERP	0.3	0.3
Employee Transfers	3.2	4
Benefit Obligation as of End of Year	(1,030)	(1,330.9)	(1,477.3)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	1,323.8	1,043.1
Actual Return on Plan Assets	(85.3)	250.4
Employer Contributions	0	98.9
Benefits Paid - Pension	(63.3)	(64.6)
Benefits Paid - Lump Sum	0	0
Employee Transfers	(3.2)	(4)
Fair Value of Plan Assets as of End of Year	1,172	1,323.8	1,043.1
Funded Status as of December 31st	142	(7.1)
CL&P | PBOP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(165.5)	(178.6)
Service Cost	(2)	(2.3)	(1.7)
Interest Cost	(3.7)	(3.2)	(4.4)
Actuarial Gain	33	5.8
Benefits Paid	10.4	10.9
Employee Transfers	(0.1)	1.9
Impact of Acquisitions	0	0
Benefit Obligation as of End of Year	(127.9)	(165.5)	(178.6)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	145.7	134.1
Actual Return on Plan Assets	(15)	24.1
Employer Contributions	0	0
Benefits Paid - Pension	(10.4)	(10.9)
Employee Transfers	0.3	(1.6)
Fair Value of Plan Assets as of End of Year	120.6	145.7	134.1
Funded Status as of December 31st	(7.3)	(19.8)
NSTAR Electric | Pension and SERP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(1,448.4)	(1,517.9)
Service Cost	(13.8)	(15.8)	(15.4)
Interest Cost	(32.8)	(26.8)	(38.6)
Actuarial Gain	295.5	20.8
Benefits Paid	68.4	68.7
Benefits Paid - Lump Sum	14.8	15.6
Benefits Paid - SERP	0.2	0.2
Employee Transfers	5.7	6.8
Benefit Obligation as of End of Year	(1,110.4)	(1,448.4)	(1,517.9)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	1,596	1,345.1
Actual Return on Plan Assets	(103.3)	312
Employer Contributions	15	30
Benefits Paid - Pension	(68.4)	(68.7)
Benefits Paid - Lump Sum	(14.8)	(15.6)
Employee Transfers	(5.7)	(6.8)
Fair Value of Plan Assets as of End of Year	1,418.8	1,596	1,345.1
Funded Status as of December 31st	308.4	147.6
NSTAR Electric | PBOP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(238.4)	(260.5)
Service Cost	(2)	(2.4)	(2.1)
Interest Cost	(5.3)	(4.4)	(6.6)
Actuarial Gain	39.4	11.5
Benefits Paid	16.6	16.3
Employee Transfers	0.2	1.1
Impact of Acquisitions	0	0
Benefit Obligation as of End of Year	(189.5)	(238.4)	(260.5)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	530	464.6
Actual Return on Plan Assets	(57)	84.2
Employer Contributions	0	0
Benefits Paid - Pension	(16.6)	(16.3)
Employee Transfers	(0.3)	(2.5)
Fair Value of Plan Assets as of End of Year	456.1	530	464.6
Funded Status as of December 31st	266.6	291.6
PSNH | Pension and SERP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(721)	(748.7)
Service Cost	(6.9)	(8.9)	(8.2)
Interest Cost	(16.9)	(14.5)	(19.4)
Actuarial Gain	156.7	14.7
Benefits Paid	33.9	34.7
Benefits Paid - Lump Sum	1	0
Benefits Paid - SERP	0.4	0.4
Employee Transfers	(3.4)	1.3
Benefit Obligation as of End of Year	(556.2)	(721)	(748.7)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	694.6	593.7
Actual Return on Plan Assets	(45.1)	136.9
Employer Contributions	0	0
Benefits Paid - Pension	(33.9)	(34.7)
Benefits Paid - Lump Sum	(1)	0
Employee Transfers	3.4	(1.3)
Fair Value of Plan Assets as of End of Year	618	694.6	593.7
Funded Status as of December 31st	61.8	(26.4)
PSNH | PBOP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(92.3)	(109.5)
Service Cost	(1.1)	(1.2)	(0.9)
Interest Cost	(2.2)	(1.8)	(2.8)
Actuarial Gain	15.2	14.6
Benefits Paid	6	5.6
Employee Transfers	(0.2)	0
Impact of Acquisitions	0	0
Benefit Obligation as of End of Year	(74.6)	(92.3)	(109.5)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	88	79.4
Actual Return on Plan Assets	(9.8)	14.2
Employer Contributions	0	0
Benefits Paid - Pension	(6)	(5.6)
Employee Transfers	0.1	0
Fair Value of Plan Assets as of End of Year	72.3	88	$ 79.4
Funded Status as of December 31st	$ (2.3)	$ (4.3)

EMPLOYEE BENEFITS - Pension Pla

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%	7%
Pension and SERP
Defined Contribution Plan Disclosure [Line Items]
Increase (decrease) in liability as a result of a change in discount rate	$ (1,480)	$ (286.8)
Expected long-term rate of return	8.25%	8.25%	8.25%
Estimated future employer contributions in next fiscal year	$ 5
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%
Ultimate rate	5%
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%

EMPLOYEE BENEFITS - Schedule _2

EMPLOYEE BENEFITS - Schedule of Funded Status (Details) - Pension and SERP - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 4,911.6	$ 6,337.3
CL&P
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	960.7	1,241.1
NSTAR Electric
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	1,055.1	1,376.1
PSNH
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 516.9	$ 670.3

EMPLOYEE BENEFITS - Schedule _3

EMPLOYEE BENEFITS - Schedule of Actuarial Assumptions (Details)	Dec. 31, 2022	Dec. 31, 2021
Pension and SERP | Minimum
Defined Benefit Plan Disclosure [Line Items]
Discount Rate	5.10%	2.80%
Compensation/Progression Rate	3.50%	3.50%
Pension and SERP | Maximum
Defined Benefit Plan Disclosure [Line Items]
Discount Rate	5.20%	3%
Compensation/Progression Rate	4%	4%
PBOP | Minimum
Defined Benefit Plan Disclosure [Line Items]
Discount Rate	5.20%	2.91%
PBOP | Maximum
Defined Benefit Plan Disclosure [Line Items]
Discount Rate		2.92%

EMPLOYEE BENEFITS - Schedule _4

EMPLOYEE BENEFITS - Schedule of Prepaid Assets (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	$ 1,045.5	$ 272
Less: Accrued SERP - current portion	(47.3)	(9.7)
Accrued Pension, SERP and PBOP	135.5	242.5
CL&P
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	147.9	0.4
Less: Accrued SERP - current portion	(0.3)	(0.5)
Accrued Pension, SERP and PBOP	12.9	26.8
NSTAR Electric
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	576.8	441.4
Less: Accrued SERP - current portion	(0.2)	(0.2)
Accrued Pension, SERP and PBOP	1.6	2
PSNH
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	66.4	0
Less: Accrued SERP - current portion	(0.4)	(0.5)
Accrued Pension, SERP and PBOP	6.5	30.2
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	756.7	0
Accrued liability, defined benefit pension plan	3.7	58.1
Pension Plan | CL&P
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	147.9	0.4
Accrued liability, defined benefit pension plan	0	0
Pension Plan | NSTAR Electric
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	310.2	149.8
Accrued liability, defined benefit pension plan	0	0
Pension Plan | PSNH
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	66.4	0
Accrued liability, defined benefit pension plan	0	20.6
PBOP
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	288.8	272
Accrued liability, defined benefit pension plan	12.4	18
PBOP | CL&P
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	0	0
Accrued liability, defined benefit pension plan	7.3	19.8
PBOP | NSTAR Electric
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	266.6	291.6
Accrued liability, defined benefit pension plan	0	0
PBOP | PSNH
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	0	0
Accrued liability, defined benefit pension plan	2.3	4.3
SERP
Defined Benefit Plan Disclosure [Line Items]
Accrued liability, defined benefit pension plan	166.7	176.1
SERP | CL&P
Defined Benefit Plan Disclosure [Line Items]
Accrued liability, defined benefit pension plan	5.9	7.5
SERP | NSTAR Electric
Defined Benefit Plan Disclosure [Line Items]
Accrued liability, defined benefit pension plan	1.8	2.2
SERP | PSNH
Defined Benefit Plan Disclosure [Line Items]
Accrued liability, defined benefit pension plan	$ 4.6	$ 5.8

EMPLOYEE BENEFITS - Schedule _5

EMPLOYEE BENEFITS - Schedule of Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 70.1	$ 85.8	$ 76.2
Interest Cost	154.5	130	177.8
Expected Return on Plan Assets	(523.6)	(437.5)	(400.3)
Actuarial Loss	116	243.9	202
Prior Service Cost/(Credit)	1.4	1.4	1.2
Total Net Periodic Benefit Plan Expense/(Income)	$ (181.6)	$ 23.6	56.9
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Income, Net	Other Income, Net
PBOP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 11.6	$ 13.5	10.2
Interest Cost	20.2	17.4	24.6
Expected Return on Plan Assets	(89.9)	(79.1)	(73.6)
Actuarial Loss	0	8.9	8.4
Prior Service Cost/(Credit)	(21.7)	(21.2)	(21.2)
Total Net Periodic Benefit Plan Expense/(Income)	$ (79.8)	$ (60.5)	(51.6)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Income, Net	Other Income, Net
CL&P | Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 18.7	$ 23	21.8
Interest Cost	31.3	27.3	37.3
Expected Return on Plan Assets	(106.3)	(86.8)	(79.2)
Actuarial Loss	16.2	45.5	39.2
Prior Service Cost/(Credit)	0	0	0
Total Net Periodic Benefit Plan Expense/(Income)	(40.1)	9	19.1
Intercompany Income Allocations	(16)	8	9.1
CL&P | PBOP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	2	2.3	1.7
Interest Cost	3.7	3.2	4.4
Expected Return on Plan Assets	(11.4)	(10.3)	(9.9)
Actuarial Loss	0	1.8	1.1
Prior Service Cost/(Credit)	1.1	1.1	1.1
Total Net Periodic Benefit Plan Expense/(Income)	(4.6)	(1.9)	(1.6)
Intercompany Income Allocations	(3.7)	(1.6)	(1.1)
NSTAR Electric | Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	13.8	15.8	15.4
Interest Cost	32.8	26.8	38.6
Expected Return on Plan Assets	(128.4)	(108.1)	(103)
Actuarial Loss	32.8	61.6	55.2
Prior Service Cost/(Credit)	0.3	0.3	0.3
Total Net Periodic Benefit Plan Expense/(Income)	(48.7)	(3.6)	6.5
Intercompany Income Allocations	(12.4)	8.8	8.9
NSTAR Electric | PBOP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	2	2.4	2.1
Interest Cost	5.3	4.4	6.6
Expected Return on Plan Assets	(42.4)	(36.9)	(34)
Actuarial Loss	0	2.4	2.5
Prior Service Cost/(Credit)	(17)	(17)	(17)
Total Net Periodic Benefit Plan Expense/(Income)	(52.1)	(44.7)	(39.8)
Intercompany Income Allocations	(3.6)	(1.9)	(1.4)
PSNH | Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	6.9	8.9	8.2
Interest Cost	16.9	14.5	19.4
Expected Return on Plan Assets	(56.1)	(47.5)	(44.7)
Actuarial Loss	7.9	20.7	15.6
Prior Service Cost/(Credit)	0	0	0
Total Net Periodic Benefit Plan Expense/(Income)	(24.4)	(3.4)	(1.5)
Intercompany Income Allocations	(3.6)	2.7	2.9
PSNH | PBOP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	1.1	1.2	0.9
Interest Cost	2.2	1.8	2.8
Expected Return on Plan Assets	(6.7)	(6.1)	(5.7)
Actuarial Loss	0	0.7	0.8
Prior Service Cost/(Credit)	0.4	0.4	0.4
Total Net Periodic Benefit Plan Expense/(Income)	(3)	(2)	(0.8)
Intercompany Income Allocations	$ (1.2)	$ (0.6)	$ (0.5)

EMPLOYEE BENEFITS - Schedule _6

EMPLOYEE BENEFITS - Schedule of Assumptions used To Calculate Pension and SERP and PBOP (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Expected Long-Term Rate of Return (in percent)	7%	7%
Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Expected Long-Term Rate of Return (in percent)	8.25%	8.25%	8.25%
PBOP
Defined Benefit Plan Disclosure [Line Items]
Expected Long-Term Rate of Return (in percent)	8.25%	8.25%	8.25%
Minimum | Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Discount rate (in percent)	2.20%	1.50%	2.60%
Compensation/Progression Rate (in percent)	3.50%	3.50%	3.50%
Minimum | PBOP
Defined Benefit Plan Disclosure [Line Items]
Discount rate (in percent)	2.30%	1.80%	2.70%
Maximum | Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Discount rate (in percent)	3.20%	3%	3.50%
Compensation/Progression Rate (in percent)	4%	4%	4%
Maximum | PBOP
Defined Benefit Plan Disclosure [Line Items]
Discount rate (in percent)	3.30%	3.10%	3.60%

EMPLOYEE BENEFITS - Summary of

EMPLOYEE BENEFITS - Summary of Changes in Plan Assets and Benefit Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Pension and SERP
Net Regulatory Assets [Abstract]
Actuarial (Gains)/Losses Arising During the Year	$ (431.6)	$ (961.7)
Actuarial Losses Reclassified as Net Periodic Benefit Expense	(107)	(231.2)
Prior Service (Cost)/Credit Reclassified as Net Periodic Benefit (Expense)/Income	(1.2)	(1.3)
Actuarial Loss	888.7	1,427.3
Prior Service (Credit)/Cost	4.1	5.3
OCI
Actuarial (Gains)/Losses Arising During the Year	4.6	(28.4)
Actuarial Losses Reclassified as Net Periodic Benefit Expense	(9)	(12.7)
Prior Service (Cost)/Credit Reclassified as Net Periodic Benefit (Expense)/Income	(0.2)	(0.1)
Actuarial Loss	61.9	66.3
Prior Service Cost	0.4	0.6
PBOP
Net Regulatory Assets [Abstract]
Actuarial (Gains)/Losses Arising During the Year	36.8	(181.5)
Actuarial Losses Reclassified as Net Periodic Benefit Expense	0	(8.5)
Prior Service (Cost)/Credit Reclassified as Net Periodic Benefit (Expense)/Income	21.8	21.1
Actuarial Loss	81.8	45
Prior Service (Credit)/Cost	(108.3)	(130.1)
OCI
Actuarial (Gains)/Losses Arising During the Year	(0.8)	(4)
Actuarial Losses Reclassified as Net Periodic Benefit Expense	0	(0.4)
Prior Service (Cost)/Credit Reclassified as Net Periodic Benefit (Expense)/Income	(0.1)	0.1
Actuarial Loss	2.7	3.5
Prior Service Cost	$ 0.9	$ 1

EMPLOYEE BENEFITS - Schedule _7

EMPLOYEE BENEFITS - Schedule of Estimated Future Benefit Payments (Details) $ in Millions	Dec. 31, 2022 USD ($)
Pension and SERP
Defined Contribution Plan Disclosure [Line Items]
2023	$ 401.4
2024	374.4
2025	380.1
2026	383
2027	384.1
2028 - 2032	1,901.7
PBOP
Defined Contribution Plan Disclosure [Line Items]
2023	57.9
2024	57.3
2025	56.6
2026	55.5
2027	54.4
2028 - 2032	$ 253.7

EMPLOYEE BENEFITS - Schedule _8

EMPLOYEE BENEFITS - Schedule of Long-term Rates of Return on Pension and PBOP (Details)	Dec. 31, 2022	Dec. 31, 2021
United States
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	15%	15%
Assumed Rate of Return (in percent)	8.50%	8.50%
Global
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	10%	10%
Assumed Rate of Return (in percent)	8.75%	8.75%
Non-United States
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	8%	8%
Assumed Rate of Return (in percent)	8.50%	8.50%
Emerging Markets
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	4%	4%
Assumed Rate of Return (in percent)	10%	10%
Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	13%	13%
Assumed Rate of Return (in percent)	4%	4%
Public High Yield Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	4%	4%
Assumed Rate of Return (in percent)	6.50%	6.50%
Private Debt
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	13%	13%
Assumed Rate of Return (in percent)	9%	9%
Private Equity
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	18%	18%
Assumed Rate of Return (in percent)	12%	12%
Real Assets
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	15%	15%
Assumed Rate of Return (in percent)	7.50%	7.50%

EMPLOYEE BENEFITS - Schedule _9

EMPLOYEE BENEFITS - Schedule of Asset Category (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension and SERP
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 5,806.4	$ 6,495.5	$ 5,409.2
Uncategorized	5,116.9	5,479.8
Pension and SERP | Total Assets Before 401
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	6,062	6,794
Pension and SERP | Equity securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	1,509.9	2,107.7
Uncategorized	1,102.2	1,385.2
Pension and SERP | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	1,954.4	2,062.5
Uncategorized	1,598.8	1,689.1
Pension and SERP | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	1,684.9	1,702.7
Uncategorized	1,684.9	1,702.7
Pension and SERP | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	912.8	921.1
Uncategorized	731	702.8
Pension and SERP | 401 PBOP Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	(255.6)	(298.5)
Pension and SERP | Level 1
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	866.6	1,080.4
Pension and SERP | Level 1 | Equity securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	407.7	722.5
Pension and SERP | Level 1 | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	277.1	139.6
Pending redemption settlements	138
Pension and SERP | Level 1 | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Pension and SERP | Level 1 | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	181.8	218.3
Pension and SERP | Level 2
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	78.5	233.8
Pension and SERP | Level 2 | Equity securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Pension and SERP | Level 2 | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	78.5	233.8
Pension and SERP | Level 2 | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Pension and SERP | Level 2 | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
PBOP
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	970.1	1,138.3	$ 1,004.1
Uncategorized	431.7	463.5
PBOP | Total Assets Before 401
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	714.5	839.8
PBOP | Equity securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	336.7	439.7
Uncategorized	183.5	248.3
PBOP | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	199.5	220.4
Uncategorized	141.1	125.5
PBOP | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	70.9	58.7
Uncategorized	70.9	58.7
PBOP | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	107.4	121
Uncategorized	36.2	31
PBOP | 401 PBOP Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	255.6	298.5
PBOP | Level 1
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	242.6	331.1
PBOP | Level 1 | Equity securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	153.2	191.4
PBOP | Level 1 | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	18.2	49.7
PBOP | Level 1 | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
PBOP | Level 1 | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	71.2	90
PBOP | Level 2
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	40.2	45.2
PBOP | Level 2 | Equity securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
PBOP | Level 2 | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	40.2	45.2
PBOP | Level 2 | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
PBOP | Level 2 | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 0	$ 0

EMPLOYEE BENEFITS - Defined Con

EMPLOYEE BENEFITS - Defined Contribution Plan Narrative (Details)	12 Months Ended
	Dec. 31, 2022
Defined Contribution Plan, 401K
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution (as a percentage)	100%
Percentage of employees' pay (up to)	3%
Defined Contribution Plan, Alternate Contribution 401K
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution (as a percentage)	50%
Percentage of employees' pay (up to)	8%

EMPLOYEE BENEFITS - Schedule_10

EMPLOYEE BENEFITS - Schedule of Defined Contribution Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost recognized	$ 59.9	$ 55.5	$ 49.4
CL&P
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost recognized	7.7	7	6.6
NSTAR Electric
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost recognized	12.8	12.2	11.8
PSNH
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost recognized	$ 4.8	$ 4.3	$ 4.1

EMPLOYEE BENEFITS - Share-Based

EMPLOYEE BENEFITS - Share-Based Payments Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted in incentive plan (up to) (in shares)	3,200,000
Shares available for issuance under incentive plan (in shares)	903,183	2,430,716
Shares outstanding (in shares)	300,592
Weighted average grant date fair value of restricted stock units (in dollars per share)	$ 81.07
Total unrecognized compensation expense	$ 24.5
Period for recognition	1 year 9 months 7 days
Tax effect on total share-based payments (in percentage)	26%
Excess stock benefit	$ 2.1	$ 4	$ 6.6
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in dollars per share)	$ 85.96	$ 81.89	$ 88.23
Shares outstanding (in shares)		297,270
Weighted average shares outstanding (in dollars per share)	$ 87.21	$ 83.39
Restricted stock units available (in shares)	184,540
Restricted stock unit fully vested (in shares)	329,142
Additional restricted stock unit expected to vest (in shares)	285,562
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in dollars per share)	$ 83.34	$ 76.08	$ 75.36
Shares outstanding (in shares)	457,069	436,957
Weighted average shares outstanding (in dollars per share)	$ 88.43	$ 81.41
Restricted stock units available (in shares)	311,553
Weighted average grant date fair value of restricted stock units (in dollars per share)	$ 73.15
Restricted stock unit fully vested (in shares)	90,221
CL&P
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense	$ 4
Excess stock benefit	0.7	$ 1.5	$ 2.3
NSTAR Electric
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense	6.9
Excess stock benefit	0.8	1.4	2.3
PSNH
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense	1.4
Excess stock benefit	$ 0.3	$ 0.5	$ 0.8
CL&P, NSTAR Electric and PSNH
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period for recognition	1 year 9 months 10 days
Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of graded vesting schedule under long-term incentive program	3 years
Board Members
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of graded vesting schedule under long-term incentive program	1 year

EMPLOYEE BENEFITS - Summary o_2

EMPLOYEE BENEFITS - Summary of RSU and Share Transactions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Restricted Stock Units (RSUs)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares)	594,623
Granted (in shares)	218,005
Shares issued (in shares)	(174,633)
Forfeited (in shares)	(8,261)
Ending balance (in shares)	629,734	594,623
Weighted Average Grant-Date Fair Value
Beginning balance (in dollars per share)	$ 65.70
Granted (in dollars per share)	85.96	$ 81.89	$ 88.23
Shares issued (in dollars per share)	79.89
Forfeited (in dollars per share)	85.87
Ending balance (in dollars per share)	$ 68.52	$ 65.70
Performance Shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares)	464,507
Granted (in shares)	337,406
Shares issued (in shares)	(248,981)
Forfeited (in shares)	(5,642)
Ending balance (in shares)	547,290	464,507
Weighted Average Grant-Date Fair Value
Beginning balance (in dollars per share)	$ 80.54
Granted (in dollars per share)	83.34	$ 76.08	$ 75.36
Shares issued (in dollars per share)	68.96
Forfeited (in dollars per share)	85.28
Ending balance (in dollars per share)	$ 87.49	$ 80.54

EMPLOYEE BENEFITS - Schedule_11

EMPLOYEE BENEFITS - Schedule of Compensation Expense and Income Tax Benefit (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	$ 33.4	$ 28.2	$ 33.9
Future Income Tax Benefit	8.7	7.3	8.9
CL&P
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	10	8.8	10.9
Future Income Tax Benefit	2.6	2.3	2.9
NSTAR Electric
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	10.7	9	11.3
Future Income Tax Benefit	2.8	2.3	3
PSNH
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	3.6	3	3.6
Future Income Tax Benefit	$ 0.9	$ 0.8	$ 1

EMPLOYEE BENEFITS - Schedule_12

EMPLOYEE BENEFITS - Schedule of Other Retirement Benefits (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarially-Determined Liability	$ 43.4	$ 42.8	$ 45.7
Other Retirement Benefits Expense	10.9	2.2	3.3
Retirement benefit payable	9.2
CL&P
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarially-Determined Liability	0.2	0.2	0.2
Other Retirement Benefits Expense	4	0.7	1.2
NSTAR Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarially-Determined Liability	0.1	0.1	0.1
Other Retirement Benefits Expense	3.7	0.7	1.1
PSNH
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarially-Determined Liability	1.3	1.5	1.7
Other Retirement Benefits Expense	$ 1.3	$ 0.3	$ 0.5

INCOME TAXES - Components of In

INCOME TAXES - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current Income Taxes:
Federal	$ 95,800	$ 21,500	$ 73,600
State	13,600	(21,600)	19,100
Total Current	109,400	(100)	92,700
Deferred Income Taxes, Net:
Federal	198,800	199,700	173,500
State	148,000	147,400	83,700
Total Deferred	346,779	347,056	257,154
Investment Tax Credits, Net	(2,600)	(2,800)	(3,700)
Income Tax Expense	453,574	344,223	346,186
CL&P
Current Income Taxes:
Federal	106,200	15,000	12,000
State	20,100	(7,000)	(6,100)
Total Current	126,300	8,000	5,900
Deferred Income Taxes, Net:
Federal	17,200	76,300	101,100
State	28,200	47,600	43,400
Total Deferred	45,381	123,889	144,527
Investment Tax Credits, Net	(500)	(600)	(700)
Income Tax Expense	171,198	131,273	149,702
NSTAR Electric
Current Income Taxes:
Federal	55,000	52,300	53,900
State	8,700	6,200	6,900
Total Current	63,700	58,500	60,800
Deferred Income Taxes, Net:
Federal	35,600	16,300	33,800
State	42,400	41,200	38,800
Total Deferred	78,039	57,507	72,595
Investment Tax Credits, Net	(1,700)	(1,700)	(2,600)
Income Tax Expense	139,977	114,335	130,828
PSNH
Current Income Taxes:
Federal	29,600	43,100	20,600
State	5,900	10,800	3,800
Total Current	35,500	53,900	24,400
Deferred Income Taxes, Net:
Federal	5,900	(14,900)	(1,300)
State	9,900	400	8,600
Total Deferred	15,765	(14,530)	7,337
Investment Tax Credits, Net	0	0	0
Income Tax Expense	$ 51,314	$ 39,433	$ 31,680

INCOME TAXES - Reconciliation B

INCOME TAXES - Reconciliation Between Income Tax Expense and Expected Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Contingency [Line Items]
Income Before Income Tax Expense	$ 1,865,968	$ 1,572,269	$ 1,558,872
Statutory Federal Income Tax Expense at 21%	391,900	330,200	327,400
Tax Effect of Differences:
Depreciation	(17,100)	(18,100)	(11,100)
Investment Tax Credit Amortization	(2,600)	(2,800)	(3,700)
State Income Taxes, Net of Federal Impact	75,900	54,400	44,900
Dividends on ESOP	(5,100)	(5,100)	(5,100)
Tax Asset Valuation   Allowance/Reserve Adjustments	51,600	44,600	33,400
Excess Stock Benefit	(2,100)	(4,000)	(6,600)
EDIT Amortization	(49,100)	(69,100)	(48,700)
Other, Net	10,200	14,100	15,700
Income Tax Expense	$ 453,574	$ 344,223	$ 346,186
Effective Tax Rate	24.30%	21.90%	22.20%
CL&P
Income Tax Contingency [Line Items]
Income Before Income Tax Expense	$ 704,118	$ 532,998	$ 607,636
Statutory Federal Income Tax Expense at 21%	147,900	111,900	127,600
Tax Effect of Differences:
Depreciation	(3,700)	(6,400)	400
Investment Tax Credit Amortization	(500)	(600)	(700)
State Income Taxes, Net of Federal Impact	(6,600)	(4,600)	(1,200)
Tax Asset Valuation   Allowance/Reserve Adjustments	44,700	36,700	30,700
Excess Stock Benefit	(700)	(1,500)	(2,300)
EDIT Amortization	(9,200)	(9,800)	(9,000)
Other, Net	(700)	5,600	4,200
Income Tax Expense	$ 171,198	$ 131,273	$ 149,702
Effective Tax Rate	24.30%	24.60%	24.60%
NSTAR Electric
Income Tax Contingency [Line Items]
Income Before Income Tax Expense	$ 632,405	$ 590,904	$ 575,829
Statutory Federal Income Tax Expense at 21%	132,800	124,100	120,900
Tax Effect of Differences:
Depreciation	(4,200)	(3,400)	(3,700)
Investment Tax Credit Amortization	(1,700)	(1,700)	(2,600)
State Income Taxes, Net of Federal Impact	40,300	37,500	36,000
Tax Asset Valuation   Allowance/Reserve Adjustments	0	0	0
Excess Stock Benefit	(800)	(1,400)	(2,300)
EDIT Amortization	(29,200)	(43,200)	(20,400)
Other, Net	2,800	2,400	2,900
Income Tax Expense	$ 139,977	$ 114,335	$ 130,828
Effective Tax Rate	22.10%	19.30%	22.70%
PSNH
Income Tax Contingency [Line Items]
Income Before Income Tax Expense	$ 222,884	$ 189,771	$ 178,992
Statutory Federal Income Tax Expense at 21%	46,800	39,900	37,600
Tax Effect of Differences:
Depreciation	900	(200)	(1,400)
Investment Tax Credit Amortization	0	0	0
State Income Taxes, Net of Federal Impact	12,500	8,900	9,800
Tax Asset Valuation   Allowance/Reserve Adjustments	0	0	0
Excess Stock Benefit	(300)	(500)	(800)
EDIT Amortization	(7,700)	(10,500)	(15,400)
Other, Net	(900)	1,800	1,900
Income Tax Expense	$ 51,314	$ 39,433	$ 31,680
Effective Tax Rate	23%	20.80%	17.70%

INCOME TAXES - Temporary Differ

INCOME TAXES - Temporary Differences That Give Rise To Accumulated Deferred Income Tax Obligations (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Deferred Tax Assets:
Employee Benefits	$ 228.9	$ 270.8
Derivative Liabilities	53.8	76.8
Regulatory Deferrals - Liabilities	529.5	390.7
Allowance for Uncollectible Accounts	125.5	104.1
Tax Effect - Tax Regulatory Liabilities	762.9	783.4
Net Operating Loss Carryforwards	16.7	7.5
Purchase Accounting Adjustment	62	67.2
Other	176.6	196.6
Total Deferred Tax Assets	1,955.9	1,897.1
Less:  Valuation Allowance	82.8	61.5
Net Deferred Tax Assets	1,873.1	1,835.6
Deferred Tax Liabilities:
Accelerated Depreciation and Other   Plant-Related Differences	4,793.7	4,426
Property Tax Accruals	95.3	88.1
Regulatory Amounts:
Regulatory Deferrals - Assets	1,251.9	1,260.3
Tax Effect - Tax Regulatory Assets	271.7	257.8
Goodwill-related Regulatory Asset - 1999 Merger	76.8	81.4
Employee Benefits	305.5	174.7
Derivative Assets	10.5	14.9
Other	135.6	129.5
Total Deferred Tax Liabilities	6,941	6,432.7
CL&P
Deferred Tax Assets:
Employee Benefits	25.3	23.9
Derivative Liabilities	53.8	76.8
Regulatory Deferrals - Liabilities	146.6	90.9
Allowance for Uncollectible Accounts	60.5	48.8
Tax Effect - Tax Regulatory Liabilities	324.6	328.2
Net Operating Loss Carryforwards	0	0
Purchase Accounting Adjustment	0	0
Other	109.5	103.9
Total Deferred Tax Assets	720.3	672.5
Less:  Valuation Allowance	63.3	44.5
Net Deferred Tax Assets	657	628
Deferred Tax Liabilities:
Accelerated Depreciation and Other   Plant-Related Differences	1,602	1,509.5
Property Tax Accruals	40.7	40.5
Regulatory Amounts:
Regulatory Deferrals - Assets	406.4	438.3
Tax Effect - Tax Regulatory Assets	185.6	181.4
Goodwill-related Regulatory Asset - 1999 Merger	0	0
Employee Benefits	45	3.5
Derivative Assets	10.5	14.9
Other	6.8	2
Total Deferred Tax Liabilities	2,297	2,190.1
NSTAR Electric
Deferred Tax Assets:
Employee Benefits	57.4	40.3
Derivative Liabilities	0	0
Regulatory Deferrals - Liabilities	285.7	215.4
Allowance for Uncollectible Accounts	20.7	21.5
Tax Effect - Tax Regulatory Liabilities	241.8	254.3
Net Operating Loss Carryforwards	0	0
Purchase Accounting Adjustment	0	0
Other	20.5	21.7
Total Deferred Tax Assets	626.1	553.2
Less:  Valuation Allowance	0	0
Net Deferred Tax Assets	626.1	553.2
Deferred Tax Liabilities:
Accelerated Depreciation and Other   Plant-Related Differences	1,643.7	1,553.7
Property Tax Accruals	41.3	33.7
Regulatory Amounts:
Regulatory Deferrals - Assets	407.9	337.6
Tax Effect - Tax Regulatory Assets	10.7	10.9
Goodwill-related Regulatory Asset - 1999 Merger	65.9	69.9
Employee Benefits	140.8	107.1
Derivative Assets	0	0
Other	16.7	19.8
Total Deferred Tax Liabilities	2,327	2,132.7
PSNH
Deferred Tax Assets:
Employee Benefits	11.6	14.1
Derivative Liabilities	0	0
Regulatory Deferrals - Liabilities	42.1	24.3
Allowance for Uncollectible Accounts	7.9	6.2
Tax Effect - Tax Regulatory Liabilities	97.8	100.9
Net Operating Loss Carryforwards	0	0
Purchase Accounting Adjustment	0	0
Other	21.3	22.9
Total Deferred Tax Assets	180.7	168.4
Less:  Valuation Allowance	0	0
Net Deferred Tax Assets	180.7	168.4
Deferred Tax Liabilities:
Accelerated Depreciation and Other   Plant-Related Differences	523.8	482.9
Property Tax Accruals	6.7	6.3
Regulatory Amounts:
Regulatory Deferrals - Assets	165.2	198.4
Tax Effect - Tax Regulatory Assets	7.9	8.3
Goodwill-related Regulatory Asset - 1999 Merger	0	0
Employee Benefits	18.7	0.7
Derivative Assets	0	0
Other	21.2	9.8
Total Deferred Tax Liabilities	$ 743.5	$ 706.4

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Accrued interest payable	$ 0.1	$ 0.1
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Valuation allowance for tax credit and operating loss carryforward	82.8	61.5
State and Local Jurisdiction | CL&P
Operating Loss Carryforwards [Line Items]
Change in valuation allowance	18.8	10.8
Eversource | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Change in valuation allowance	$ 21.3	$ 13

INCOME TAXES - Tax Credits and

INCOME TAXES - Tax Credits and Loss Carryforwards (Details) - State and Local Jurisdiction - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
State Net Operating Loss	$ 288.1	$ 138.3
State Tax Credit	204.5	197.7
State Charitable Contribution	20.1	23.7
CL&P
Operating Loss Carryforwards [Line Items]
State Net Operating Loss	0	0
State Tax Credit	137.7	137
State Charitable Contribution	0	0
NSTAR Electric
Operating Loss Carryforwards [Line Items]
State Net Operating Loss	0	0
State Tax Credit	0	0
State Charitable Contribution	0	0
PSNH
Operating Loss Carryforwards [Line Items]
State Net Operating Loss	0	0
State Tax Credit	0	0
State Charitable Contribution	$ 0	$ 0

INCOME TAXES - Reconciliation o

INCOME TAXES - Reconciliation of Unrecognized Tax Benefit (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning Balance	$ 65.8	$ 61.8	$ 55
Gross Increases - Current Year	11.5	11.3	11.9
Gross Increases - Prior Year			1.4
Gross Decreases - Prior Year	(2.4)	(0.3)
Lapse of Statute of Limitations	(7.8)	(7)	(6.5)
Ending Balance	67.1	65.8	61.8
CL&P
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning Balance	26.2	25.8	23.1
Gross Increases - Current Year	3.5	3.8	4.6
Gross Increases - Prior Year			0.7
Gross Decreases - Prior Year	(0.9)	(0.6)
Lapse of Statute of Limitations	(3.3)	(2.8)	(2.6)
Ending Balance	$ 25.5	$ 26.2	$ 25.8

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Schedule of Reconciliation of Activity in Environmental Reserve (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accrual for Environmental Loss Contingencies [Roll Forward]
Accrual for Environmental Loss Contingencies, Beginning Balance	$ 115.4	$ 102.4
Additions	12.6	23.4
Payments/Reductions	(5.4)	(10.4)
Accrual for Environmental Loss Contingencies, Ending Balance	$ 122.6	$ 115.4
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]	Other Current Liabilities	Other Current Liabilities	Other Current Liabilities
CL&P
Accrual for Environmental Loss Contingencies [Roll Forward]
Accrual for Environmental Loss Contingencies, Beginning Balance	$ 13.9	$ 12.3
Additions	0.9	4.4
Payments/Reductions	(0.9)	(2.8)
Accrual for Environmental Loss Contingencies, Ending Balance	13.9	13.9
NSTAR Electric
Accrual for Environmental Loss Contingencies [Roll Forward]
Accrual for Environmental Loss Contingencies, Beginning Balance	3.3	4.7
Additions	0.4	0
Payments/Reductions	(0.3)	(1.4)
Accrual for Environmental Loss Contingencies, Ending Balance	3.4	3.3
PSNH
Accrual for Environmental Loss Contingencies [Roll Forward]
Accrual for Environmental Loss Contingencies, Beginning Balance	6.3	7.1
Additions	0.5	0
Payments/Reductions	(0.7)	(0.8)
Accrual for Environmental Loss Contingencies, Ending Balance	$ 6.1	$ 6.3

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES - Schedule of Number of Sites and Reserves (Details) - site	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Loss Contingencies [Line Items]
Number of Sites	59	61
CL&P
Loss Contingencies [Line Items]
Number of Sites	13	14
NSTAR Electric
Loss Contingencies [Line Items]
Number of Sites	10	11
PSNH
Loss Contingencies [Line Items]
Number of Sites	8	9

COMMITMENTS AND CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES - Environmental Matters Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) site	Dec. 31, 2021 USD ($) site	Dec. 31, 2020 USD ($)
Loss Contingencies [Line Items]
Number of sites | site	59	61
Reserve	$ 122.6	$ 115.4	$ 102.4
CL&P
Loss Contingencies [Line Items]
Number of sites | site	13	14
Reserve	$ 13.9	$ 13.9	12.3
NSTAR Electric
Loss Contingencies [Line Items]
Number of sites | site	10	11
Reserve	$ 3.4	$ 3.3	4.7
PSNH
Loss Contingencies [Line Items]
Number of sites | site	8	9
Reserve	$ 6.1	$ 6.3	$ 7.1
MGP Site accrual
Loss Contingencies [Line Items]
Reserve balances related to former MGP sites	$ 112.6	$ 105.6
Environmental Sites for Which a Range of Loss Exists
Loss Contingencies [Line Items]
Number of sites | site	7
Reserve	$ 29.9
Best estimate of potential remediation costs (up to)	$ 17
Environmental Sites for Which a Range of Loss Exists | CL&P
Loss Contingencies [Line Items]
Number of sites | site	1
Reserve	$ 0.6
Best estimate of potential remediation costs (up to)	$ 0.3
Environmental Site for Which a Range is Too Early to Determine
Loss Contingencies [Line Items]
Number of sites | site	15
Reserve	$ 25.8
Environmental Site for Which a Range is Too Early to Determine | CL&P
Loss Contingencies [Line Items]
Number of sites | site	7
Reserve	$ 4.4
Environmental Site for Which a Range is Too Early to Determine | NSTAR Electric
Loss Contingencies [Line Items]
Number of sites | site	1
Reserve	$ 0.1
Evironmental Sites with Best Estimate
Loss Contingencies [Line Items]
Number of sites | site	37
Reserve	$ 66.9
Evironmental Sites with Best Estimate | CL&P
Loss Contingencies [Line Items]
Reserve	$ 8.9
Environmental site quantity remaining | site	5
Evironmental Sites with Best Estimate | NSTAR Electric
Loss Contingencies [Line Items]
Reserve	$ 3.3
Environmental site quantity remaining | site	9
Evironmental Sites with Best Estimate | PSNH
Loss Contingencies [Line Items]
Reserve	$ 6.1
Environmental site quantity remaining | site	8

COMMITMENTS AND CONTINGENCIES_4

COMMITMENTS AND CONTINGENCIES - Schedule of Estimated Future Annual Costs of Long term Contractual Agreement (Details) $ in Millions	Dec. 31, 2022 USD ($)
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	$ 1,324.6
2024	1,500.6
2025	1,411.4
2026	1,323
2027	1,304.6
Thereafter	9,685.9
Total	16,550.1
Renewable Energy Purchase Contracts
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	751.8
2024	952.6
2025	954.8
2026	983
2027	998.5
Thereafter	8,141.1
Total	12,781.8
Natural Gas Procurement
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	447.1
2024	419.4
2025	340.9
2026	298.5
2027	269.4
Thereafter	1,450.6
Total	3,225.9
Purchased Power and Capacity
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	87.6
2024	86.8
2025	75.2
2026	2.9
2027	2.7
Thereafter	7.2
Total	262.4
Peaker CfDs
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	20.3
2024	21.1
2025	17.9
2026	16
2027	11.4
Thereafter	64.4
Total	151.1
Transmission Support Commitments
Transmission Support Commitments
2023	17.8
2024	20.7
2025	22.6
2026	22.6
2027	22.6
Thereafter	22.6
Total	128.9
CL&P
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	705.6
2024	722.3
2025	709.4
2026	632.6
2027	629.3
Thereafter	2,326.4
Total	5,725.6
CL&P | Renewable Energy Purchase Contracts
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	594.8
2024	609.1
2025	610.2
2026	607.6
2027	609
Thereafter	2,253.1
Total	5,283.8
CL&P | Purchased Power and Capacity
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	83.5
2024	83.9
2025	72.4
2026	0.1
2027	0
Thereafter	0
Total	239.9
CL&P | Peaker CfDs
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	20.3
2024	21.1
2025	17.9
2026	16
2027	11.4
Thereafter	64.4
Total	151.1
CL&P | Transmission Support Commitments
Transmission Support Commitments
2023	7
2024	8.2
2025	8.9
2026	8.9
2027	8.9
Thereafter	8.9
Total	50.8
NSTAR Electric
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	89.1
2024	281
2025	328.2
2026	334.6
2027	340.2
Thereafter	5,535.9
Total	6,909
NSTAR Electric | Renewable Energy Purchase Contracts
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	79.2
2024	270
2025	316.5
2026	322.9
2027	328.6
Thereafter	5,519.8
Total	6,837
NSTAR Electric | Purchased Power and Capacity
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	2.9
2024	2.9
2025	2.8
2026	2.8
2027	2.7
Thereafter	7.2
Total	21.3
NSTAR Electric | Transmission Support Commitments
Transmission Support Commitments
2023	7
2024	8.1
2025	8.9
2026	8.9
2027	8.9
Thereafter	8.9
Total	50.7
PSNH
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	82.8
2024	77.9
2025	32.9
2026	57.3
2027	65.7
Thereafter	373
Total	689.6
PSNH | Renewable Energy Purchase Contracts
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	77.8
2024	73.5
2025	28.1
2026	52.5
2027	60.9
Thereafter	368.2
Total	661
PSNH | Purchased Power and Capacity
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2023	1.2
2024	0
2025	0
2026	0
2027	0
Thereafter	0
Total	1.2
PSNH | Transmission Support Commitments
Transmission Support Commitments
2023	3.8
2024	4.4
2025	4.8
2026	4.8
2027	4.8
Thereafter	4.8
Total	$ 27.4

COMMITMENTS AND CONTINGENCIES_5

COMMITMENTS AND CONTINGENCIES - Long-Term Contractual Arrangement Narrative (Details) MWh in Millions, $ in Millions					12 Months Ended
	Oct. 31, 2020	Nov. 22, 2019 MW	Mar. 15, 2019 MW	Dec. 28, 2018 MWh	Dec. 31, 2022 USD ($) MW contract
Long-term Purchase Commitment [Line Items]
Estimated cost of energy purchase contracts					$ 16,550.1
Contract term					20 years
Construction in Progress
Long-term Purchase Commitment [Line Items]
Total construction contract cost					$ 6,700
Minimum
Long-term Purchase Commitment [Line Items]
Estimated costs under construction contract					150
Maximum
Long-term Purchase Commitment [Line Items]
Estimated costs under construction contract					415
Peaker Contracts For Differences
Long-term Purchase Commitment [Line Items]
Estimated cost of energy purchase contracts					$ 151.1
Percentage of costs and benefits borne by United Illuminated Company					20%
Period of payment to generation facility owner					30 years
CL&P
Long-term Purchase Commitment [Line Items]
Estimated cost of energy purchase contracts					$ 5,725.6
CL&P | Peaker Contracts For Differences
Long-term Purchase Commitment [Line Items]
Estimated cost of energy purchase contracts					$ 151.1
Number of capacity contracts | contract					3
Amount of peaking capacity contracts (in MW) | MW					500
Percentage of costs and benefits borne					80%
CL&P, NSTAR Electric and PSNH | Transmission Support Commitments
Long-term Purchase Commitment [Line Items]
Period of payment of annual operation and maintenance expense	20 years				30 years
NSTAR Electric
Long-term Purchase Commitment [Line Items]
Contract term					20 years
Estimated cost of energy purchase contracts					$ 6,909
NSTAR Electric | Construction in Progress
Long-term Purchase Commitment [Line Items]
Total construction contract cost					6,000
NSTAR Electric | Minimum
Long-term Purchase Commitment [Line Items]
Estimated costs under construction contract					240
NSTAR Electric | Maximum
Long-term Purchase Commitment [Line Items]
Estimated costs under construction contract					375
Millstone Nuclear Power Station and Seabrook Nuclear Power Plant
Long-term Purchase Commitment [Line Items]
Estimated cost of energy purchase contracts					$ 2,900
Milestone Nuclear Power Station
Long-term Purchase Commitment [Line Items]
Annual purchase requirement (in MWh) | MWh				9
Percent of the facility's output required to be purchased			50%
Nameplate capacity (in MW) | MW			2,112
Milestone Nuclear Power Station | CL&P
Long-term Purchase Commitment [Line Items]
Contract term				10 years
Percent of the facility's output required to be purchased			40%
Milestone Nuclear Power Station | UI
Long-term Purchase Commitment [Line Items]
Contract term				10 years
Seabrook Nuclear Power Plant
Long-term Purchase Commitment [Line Items]
Percent of the facility's output required to be purchased		18%
Nameplate capacity (in MW) | MW		1,250
Seabrook Nuclear Power Plant | CL&P
Long-term Purchase Commitment [Line Items]
Contract term				8 years
Percent of the facility's output required to be purchased		15%
Seabrook Nuclear Power Plant | UI
Long-term Purchase Commitment [Line Items]
Contract term				8 years
Vineyard Wind Project | NSTAR Electric
Long-term Purchase Commitment [Line Items]
Nameplate capacity (in MW) | MW					800
Contract term					20 years

COMMITMENTS AND CONTINGENCIES_6

COMMITMENTS AND CONTINGENCIES - Schedule of Total Costs Incurred (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Long-term Purchase Commitment [Line Items]
Renewable Energy Purchase Contracts	$ 678.1	$ 609.2	$ 584.2
Natural Gas Procurement	1,042.8	712.7	453.4
Purchased Power and Capacity	61.6	56.4	62.7
Peaker CfDs	13.4	24.3	22.7
Transmission Support Commitments	12.7	15.4	22.1
CL&P
Long-term Purchase Commitment [Line Items]
Renewable Energy Purchase Contracts	513.2	457.1	426.3
Purchased Power and Capacity	57.7	53.1	59.3
Peaker CfDs	13.4	24.3	22.7
Transmission Support Commitments	5	6.1	8.7
NSTAR Electric
Long-term Purchase Commitment [Line Items]
Renewable Energy Purchase Contracts	90.8	84.7	88.8
Purchased Power and Capacity	3	3	3.1
Peaker CfDs	0	0	0
Transmission Support Commitments	5	6	8.7
PSNH
Long-term Purchase Commitment [Line Items]
Renewable Energy Purchase Contracts	74.1	67.4	69.1
Purchased Power and Capacity	0.9	0.3	0.3
Peaker CfDs	0	0	0
Transmission Support Commitments	$ 2.7	$ 3.3	$ 4.7

COMMITMENTS AND CONTINGENCIES_7

COMMITMENTS AND CONTINGENCIES - Spent Nuclear Fuel Obligations Narrative (Details) - USD ($) $ in Millions	Jun. 08, 2022	Mar. 25, 2021
Yankee Companies
Guarantor Obligations [Line Items]
Damages sought	$ 33.1	$ 120.4

COMMITMENTS AND CONTINGENCIES_8

COMMITMENTS AND CONTINGENCIES - Schedule of Guarantees and Indemnifications (Details) $ in Millions	1 Months Ended
	Jan. 31, 2022 USD ($) letterOfCredit	Jan. 01, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 16, 2020 USD ($)
Guarantor Obligations [Line Items]
Exposure of guarantee			$ 4.2	$ 7.3
Eversource Investment LLC | Letter of Credit
Guarantor Obligations [Line Items]
Maximum borrowing capacity					$ 25
North East Offshore LLC
Guarantor Obligations [Line Items]
Ownership interest (in percent)			50%
Revolution Wind, LLC
Guarantor Obligations [Line Items]
Maximum Exposure			$ 546.7
Ownership interest (in percent)			50%
South Fork Wind, LLC
Guarantor Obligations [Line Items]
Maximum Exposure			$ 7.1
Ownership interest (in percent)			50%
Construction-related purchase agreements with third-party contractors | Sunrise Wind LLC
Guarantor Obligations [Line Items]
Maximum Exposure			$ 465.8
Ownership interest (in percent)			50%
Construction-related purchase agreements with third-party contractors | South Fork Wind, LLC
Guarantor Obligations [Line Items]
Maximum Exposure			$ 207.7
Ownership interest (in percent)			50%
OREC Capacity Production | Sunrise Wind LLC
Guarantor Obligations [Line Items]
Maximum Exposure			$ 15.4
Ownership interest (in percent)			50%
Exposure of guarantee			$ 2.2
OREC Capacity Production | Sunrise Wind LLC | Subsequent Event
Guarantor Obligations [Line Items]
Exposure of guarantee		$ 11
North East Offshore LLC | Construction-related purchase agreements with third-party contractors
Guarantor Obligations [Line Items]
Maximum Exposure			717.6
North East Offshore LLC | Performance Guarantee
Guarantor Obligations [Line Items]
Maximum Exposure			$ 1,300
Percent of obligations guaranteed			50%
North East Offshore LLC | Payment Guarantee
Guarantor Obligations [Line Items]
Maximum Exposure			$ 62.5
Percent of obligations guaranteed			50%
Sunrise Wind LLC | Construction-related purchase agreements with third-party contractors
Guarantor Obligations [Line Items]
Maximum Exposure			$ 311.5
Sunrise Wind LLC | OREC Capacity Production
Guarantor Obligations [Line Items]
Maximum Exposure			2.2
Revolution Wind, LLC | Construction-related purchase agreements with third-party contractors
Guarantor Obligations [Line Items]
Maximum Exposure			419.1
South Fork Wind, LLC
Guarantor Obligations [Line Items]
Letters of credit issued | letterOfCredit	2
South Fork Wind, LLC | Letter of Credit
Guarantor Obligations [Line Items]
Line of credit outstanding	$ 4.3
South Fork Wind, LLC | Construction-related purchase agreements with third-party contractors
Guarantor Obligations [Line Items]
Maximum Exposure			142.1
South Fork Wind, LLC | Power Purchase Agreement Security
Guarantor Obligations [Line Items]
Maximum Exposure			7.1
South Fork Wind, LLC | Transmission interconnection
Guarantor Obligations [Line Items]
Maximum Exposure			$ 1.2
Eversource Investment LLC | North East Offshore LLC
Guarantor Obligations [Line Items]
Ownership interest (in percent)			50%
Eversource Investment LLC | Funding and Indemnification Obligations
Guarantor Obligations [Line Items]
Maximum Exposure			$ 77
Eversource Investment LLC | Funding and Indemnification Obligations | North East Offshore LLC
Guarantor Obligations [Line Items]
Maximum Exposure			910
Eversource Investment LLC | Letters of Credit
Guarantor Obligations [Line Items]
Maximum Exposure			4.3
Bay State Wind LLC | Real estate purchase
Guarantor Obligations [Line Items]
Maximum Exposure			2.5
Various | Surety Bonds
Guarantor Obligations [Line Items]
Maximum Exposure			35.7
Eversource Service | Lease payments for real estate
Guarantor Obligations [Line Items]
Maximum Exposure			$ 0.5

COMMITMENTS AND CONTINGENCIES_9

COMMITMENTS AND CONTINGENCIES - Guarantees and Obligations Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 14, 2022	Nov. 30, 2022	Jun. 14, 2022
Line of Credit | PSNH
Loss Contingencies [Line Items]
Amount of long-term debt requested for issuance		$ 600
Line of Credit | CL&P
Loss Contingencies [Line Items]
Amount of long-term debt requested for issuance			$ 1,150
Line of Credit | NSTAR Gas
Loss Contingencies [Line Items]
Amount of long-term debt requested for issuance				$ 325
Sunrise Wind LLC | Forecast | Subsequent Event
Loss Contingencies [Line Items]
Maximum exposure	$ 58.1

COMMITMENTS AND CONTINGENCIE_10

COMMITMENTS AND CONTINGENCIES - FERC ROE Complaints Narrative (Details) $ in Millions			12 Months Ended	30 Months Ended	36 Months Ended
	Oct. 16, 2018 complaint	Apr. 29, 2016 complaint	Dec. 31, 2022 USD ($)	Apr. 14, 2017	Oct. 15, 2014	Dec. 31, 2021 USD ($)	Jul. 31, 2014 complaint
Loss Contingencies [Line Items]
Percentage of base ROE reasonably justified	10.41%
Percentage of incentive cap on total ROE	13.08%
FERC ROE Complaints
Loss Contingencies [Line Items]
Loss contingency, pending claims, number | complaint	4	4
Period of complaint			15 months
Basis point change			0.10%
Estimate of possible loss for each 10 basis point change to base ROE			$ 3
Complaint period			15 months
FERC ROE First, Second and Third Complaints
Loss Contingencies [Line Items]
Loss contingency, pending claims, number | complaint							3
Base ROE percentage challenged by complainants			11.14%
Percentage of ROE for any incentive project	13.08%
FERC ROE First Complaint
Loss Contingencies [Line Items]
Percentage of ROE for any incentive project				11.74%
Refund payments			$ 38.9
FERC ROE Second Complaint
Loss Contingencies [Line Items]
Percentage of base ROE of complaint period			10.57%	10.57%
Percentage of ROE for any incentive project			11.74%
Loss contingency, estimate of possible earnings impact			$ 39.1
FERC ROE Fourth Complaint
Loss Contingencies [Line Items]
Percentage of base ROE of complaint period		10.57%
Maximum percentage cap of ROE for incentive projects		11.74%
Percentage of ROE for any incentive project			10.57%
Original base ROE authorized by FERC at time of complaint			11.74%
FERC MISO Complaints
Loss Contingencies [Line Items]
Loss contingency, pending claims, number | complaint	2
CL&P | FERC ROE First Complaint
Loss Contingencies [Line Items]
Refund payments			$ 22.4
CL&P | FERC ROE Second Complaint
Loss Contingencies [Line Items]
Loss contingency, estimate of possible earnings impact			21.4			$ 21.4
NSTAR Electric | FERC ROE First Complaint
Loss Contingencies [Line Items]
Refund payments			13.7
NSTAR Electric | FERC ROE Second Complaint
Loss Contingencies [Line Items]
Loss contingency, estimate of possible earnings impact			14.6			14.6
PSNH | FERC ROE First Complaint
Loss Contingencies [Line Items]
Refund payments			2.8
PSNH | FERC ROE Second Complaint
Loss Contingencies [Line Items]
Loss contingency, estimate of possible earnings impact			$ 3.1			$ 3.1
Minimum | FERC ROE First, Second and Third Complaints
Loss Contingencies [Line Items]
Percentage of ROE for any incentive project					11.14%
Maximum | FERC ROE First, Second and Third Complaints
Loss Contingencies [Line Items]
Percentage of ROE for any incentive project					13.10%

COMMITMENTS AND CONTINGENCIE_11

COMMITMENTS AND CONTINGENCIES - Eversource and NSTAR Electric Boston Harbor Civil Action Narrative (Details)	Jul. 15, 2016 kV
Commitments and Contingencies Disclosure [Abstract]
Amount of capacity required for installation of distribution cable (in kV)	115

COMMITMENTS AND CONTINGENCIE_12

COMMITMENTS AND CONTINGENCIES - CL&P Tropical Storm Isaias Response Investigation (Details) $ in Millions	Jul. 14, 2021 USD ($)	May 07, 2021	Apr. 28, 2021
Loss Contingencies [Line Items]
Loss contingency, allowed rate of ROE, downward adjustment			0.0090
Loss contingency, allowed rate of ROE (in percent)			9.25%
Unfavorable Regulatory Action
Loss Contingencies [Line Items]
Non-compliance fine	$ 28.6
Loss contingency, accident reporting violation fines	$ 0.2
Loss contingency, penalty rate as a percent of distribution revenues		2.50%

COMMITMENTS AND CONTINGENCIE_13

COMMITMENTS AND CONTINGENCIES - CL&P Comprehensive Settlement Agreement (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Oct. 01, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2022	Dec. 31, 2019
Loss Contingencies [Line Items]
Bill of forgiveness		$ 521,752	$ 221,008	$ 264,950		$ 117,063
Regulatory Liabilities		890,786	602,432
Loss related to litigation settlement		(72,041)	81,274	0
Basis points reduction to return on equity, scenario one	0.90%
Basis points reduction to return on equity, scenario two	0.45%
CL&P
Loss Contingencies [Line Items]
Bill of forgiveness		20,327	74,788	99,809		$ 4,971
Regulatory Liabilities		336,048	266,489
Loss related to litigation settlement		(72,041)	81,274	$ 0
CL&P | Customer Assistance Fund
Loss Contingencies [Line Items]
Bill of forgiveness					$ 10,000
Unfavorable Regulatory Action
Loss Contingencies [Line Items]
Loss related to litigation settlement		103,600
Customer credits and assistance	$ 75,000
Loss related to litigation settlement, net of tax		$ 86,100
Loss contingency, after-tax earnings impact per share (in dollars per share)		$ 0.25
Unfavorable Regulatory Action | Sales
Loss Contingencies [Line Items]
Loss related to litigation settlement		$ 65,000
Unfavorable Regulatory Action | Oil and Gas, Operation and Maintenance
Loss Contingencies [Line Items]
Loss related to litigation settlement		10,000
Unfavorable Regulatory Action | CL&P
Loss Contingencies [Line Items]
Customer credits	65,000
Customer assistance initiatives	$ 10,000
Regulatory Liabilities		75,000	75,000
Unfavorable Regulatory Action | CL&P | Sales
Loss Contingencies [Line Items]
Loss related to litigation settlement			$ 65,000
Unfavorable Regulatory Action | CL&P | Oil and Gas, Operation and Maintenance
Loss Contingencies [Line Items]
Loss related to litigation settlement		$ 10,000

LEASES - Narrative (Details)

LEASES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Right-of-use assets in exchange for the assumption of new operating lease liabilities	$ 18.9	$ 2.1	$ 0.6
Right-of-use assets in exchange for the assumption of new finance lease liabilities	$ 3.5	2.3	0.7
CMA
Lessee, Lease, Description [Line Items]
Right-of-use assets in exchange for the assumption of new operating lease liabilities			14.7
Right-of-use assets in exchange for the assumption of new finance lease liabilities			54.2
Minimum
Lessee, Lease, Description [Line Items]
Renewal period	1 year
Maximum
Lessee, Lease, Description [Line Items]
Renewal period	20 years
CL&P
Lessee, Lease, Description [Line Items]
Right-of-use assets in exchange for the assumption of new operating lease liabilities	$ 2.4	0	0.1
Right-of-use assets in exchange for the assumption of new finance lease liabilities	$ 0	0	0
CL&P | Minimum
Lessee, Lease, Description [Line Items]
Renewal period	1 year
CL&P | Maximum
Lessee, Lease, Description [Line Items]
Renewal period	20 years
NSTAR Electric
Lessee, Lease, Description [Line Items]
Right-of-use assets in exchange for the assumption of new operating lease liabilities	$ 0	1.9	0.2
Right-of-use assets in exchange for the assumption of new finance lease liabilities	$ 0	0	0.3
NSTAR Electric | Minimum
Lessee, Lease, Description [Line Items]
Renewal period	1 year
NSTAR Electric | Maximum
Lessee, Lease, Description [Line Items]
Renewal period	20 years
PSNH
Lessee, Lease, Description [Line Items]
Right-of-use assets in exchange for the assumption of new operating lease liabilities	$ 0	0	0
Right-of-use assets in exchange for the assumption of new finance lease liabilities	$ 0	$ 0	$ 0
PSNH | Minimum
Lessee, Lease, Description [Line Items]
Renewal period	1 year
PSNH | Maximum
Lessee, Lease, Description [Line Items]
Renewal period	20 years

LEASES - Components of Lease Co

LEASES - Components of Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Lease, Cost [Abstract]
Amortization of Right-of-use-Assets	$ 8.3	$ 4.6	$ 2.6
Interest on Lease Liabilities	2	3.9	1.4
Total Finance Lease Cost	10.3	8.5	4
Operating Lease Cost	11.6	12.2	11.1
Variable Lease Cost	78.1	61	57.8
Total Lease Cost	100	81.7	72.9
CL&P
Lease, Cost [Abstract]
Amortization of Right-of-use-Assets	0	0.5	0.7
Interest on Lease Liabilities	0	0.1	0.3
Total Finance Lease Cost	0	0.6	1
Operating Lease Cost	0.3	0.3	0.6
Variable Lease Cost	25.6	16.2	12.2
Total Lease Cost	25.9	17.1	13.8
NSTAR Electric
Lease, Cost [Abstract]
Amortization of Right-of-use-Assets	0.2	0.2	0.2
Interest on Lease Liabilities	0.6	0.6	0.6
Total Finance Lease Cost	0.8	0.8	0.8
Operating Lease Cost	2.3	2.3	2.1
Variable Lease Cost	0	0	0
Total Lease Cost	3.1	3.1	2.9
PSNH
Lease, Cost [Abstract]
Amortization of Right-of-use-Assets	0.1	0.1	0.1
Interest on Lease Liabilities	0	0	0
Total Finance Lease Cost	0.1	0.1	0.1
Operating Lease Cost	0.1	0.1	0.1
Variable Lease Cost	52.5	44.8	45.6
Total Lease Cost	$ 52.7	$ 45	$ 45.8

LEASES - Supplemental Balance S

LEASES - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Operating Leases:
Right-of-use-Assets, Net	$ 56.9	$ 47.2
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other Long-Term Assets	Other Long-Term Assets
Current Portion	$ 9	$ 10
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other Current Liabilities	Other Current Liabilities
Long-Term	$ 47.9	$ 37.2
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Long-Term Liabilities	Other Long-Term Liabilities
Total Operating Lease Liabilities	$ 56.9	$ 47.2
Finance Leases:
Right-of-use-Assets, Net	$ 54.5	$ 58
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, Plant and Equipment, Net	Property, Plant and Equipment, Net
Current Portion	$ 3.8	$ 3.9
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other Current Liabilities	Other Current Liabilities
Long-Term	$ 54.2	$ 55.4
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Long-Term Liabilities	Other Long-Term Liabilities
Total Finance Lease Liabilities	$ 58	$ 59.3
CL&P
Operating Leases:
Right-of-use-Assets, Net	2.2	0.1
Current Portion	0.6	0.1
Long-Term	1.6	0
Total Operating Lease Liabilities	2.2	0.1
Finance Leases:
Right-of-use-Assets, Net	0	0
Current Portion	0	0
Long-Term	0	0
Total Finance Lease Liabilities	0	0
NSTAR Electric
Operating Leases:
Right-of-use-Assets, Net	22.5	24.3
Current Portion	1.2	1.1
Long-Term	21.3	23.2
Total Operating Lease Liabilities	22.5	24.3
Finance Leases:
Right-of-use-Assets, Net	3.2	3.3
Current Portion	0	0
Long-Term	4.9	4.9
Total Finance Lease Liabilities	4.9	4.9
PSNH
Operating Leases:
Right-of-use-Assets, Net	0	0.3
Current Portion	0	0
Long-Term	0	0.3
Total Operating Lease Liabilities	0	0.3
Finance Leases:
Right-of-use-Assets, Net	0	0.7
Current Portion	0	0.1
Long-Term	0	0.6
Total Finance Lease Liabilities	$ 0	$ 0.7

LEASES - Other Information Rela

LEASES - Other Information Related to Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Weighted-Average Remaining Lease Term (Years):
Operating Leases	11 years	13 years
Finance Leases	15 years	16 years
Weighted-Average Discount Rate (Percentage):
Operating Leases	3.20%	4.10%
Finance Leases	2.70%	2.70%
Cash Paid for Amounts Included in the Measurement of Lease Liabilities:
Operating Cash Flows from Operating Leases	$ 11.3	$ 12.1	$ 10.9
Operating Cash Flows from Finance Leases	2	3.4	1.7
Financing Cash Flows from Finance Leases	3.9	4.1	2.8
Supplemental Non-Cash Information on Lease Liabilities:
Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities	18.9	2.1	0.6
Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities	$ 3.5	$ 2.3	0.7
CL&P
Weighted-Average Remaining Lease Term (Years):
Operating Leases	4 years	7 years
Weighted-Average Discount Rate (Percentage):
Operating Leases	3.80%	3%
Finance Leases	0%	0%
Cash Paid for Amounts Included in the Measurement of Lease Liabilities:
Operating Cash Flows from Operating Leases	$ 0.3	$ 0.3	0.6
Operating Cash Flows from Finance Leases	0	0.1	0.3
Financing Cash Flows from Finance Leases	0	1.4	1.6
Supplemental Non-Cash Information on Lease Liabilities:
Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities	2.4	0	0.1
Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities	$ 0	$ 0	0
NSTAR Electric
Weighted-Average Remaining Lease Term (Years):
Operating Leases	17 years	18 years
Finance Leases	19 years	20 years
Weighted-Average Discount Rate (Percentage):
Operating Leases	4%	4%
Finance Leases	2.90%	2.90%
Cash Paid for Amounts Included in the Measurement of Lease Liabilities:
Operating Cash Flows from Operating Leases	$ 2.1	$ 2.1	1.8
Operating Cash Flows from Finance Leases	0.6	0.6	0.6
Financing Cash Flows from Finance Leases	0	0	0
Supplemental Non-Cash Information on Lease Liabilities:
Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities	0	1.9	0.2
Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities	$ 0	$ 0	0.3
PSNH
Weighted-Average Remaining Lease Term (Years):
Operating Leases		7 years
Finance Leases		7 years
Weighted-Average Discount Rate (Percentage):
Operating Leases	0%	3.70%
Finance Leases	0%	3.50%
Cash Paid for Amounts Included in the Measurement of Lease Liabilities:
Operating Cash Flows from Operating Leases	$ 0.1	$ 0.1	0.1
Operating Cash Flows from Finance Leases	0	0	0
Financing Cash Flows from Finance Leases	0.1	0.1	0.1
Supplemental Non-Cash Information on Lease Liabilities:
Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities	0	0	0
Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities	$ 0	$ 0	$ 0

LEASES - Future Minimum Lease P

LEASES - Future Minimum Lease Payments under Long-Term Leases (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Operating Leases
2023	$ 10.3
2024	9.3
2025	6.4
2026	5.5
2027	5.2
Thereafter	31.2
Future lease payments	67.9
Less amount representing interest	11
Present value of future minimum lease payments	56.9	$ 47.2
Finance Leases
2023	5.9
2024	5.9
2025	5.9
2026	5.4
2027	5.4
Thereafter	50.9
Future lease payments	79.4
Less amount representing interest	21.4
Present value of future minimum lease payments	58	59.3
CL&P
Operating Leases
2023	0.7
2024	0.7
2025	0.7
2026	0.3
2027	0
Thereafter	0
Future lease payments	2.4
Less amount representing interest	0.2
Present value of future minimum lease payments	2.2	0.1
Finance Leases
Present value of future minimum lease payments	0	0
NSTAR Electric
Operating Leases
2023	2.1
2024	2.1
2025	1.7
2026	1.7
2027	1.7
Thereafter	23.6
Future lease payments	32.9
Less amount representing interest	10.4
Present value of future minimum lease payments	22.5	24.3
Finance Leases
2023	0.6
2024	0.6
2025	0.6
2026	0.7
2027	0.7
Thereafter	11.8
Future lease payments	15
Less amount representing interest	10.1
Present value of future minimum lease payments	$ 4.9	$ 4.9

FAIR VALUE OF FINANCIAL INSTR_3

FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	$ 155,570	$ 155,570
Rate Reduction Bonds	410,492	453,702
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	155,600	155,600
Long-Term Debt	21,044,100	18,216,700
Rate Reduction Bonds	453,700	496,900
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	136,700	166,300
Long-Term Debt	18,891,300	19,636,300
Rate Reduction Bonds	424,700	543,300
CL&P
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	116,200	116,200
CL&P | Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	116,200	116,200
Long-Term Debt	4,216,500	4,215,400
Rate Reduction Bonds	0	0
CL&P | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	99,200	122,300
Long-Term Debt	3,828,300	4,848,900
CL&P | Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rate Reduction Bonds	0	0
NSTAR Electric
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	43,000	43,000
NSTAR Electric | Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	43,000	43,000
Long-Term Debt	4,425,100	3,985,400
Rate Reduction Bonds	0	0
NSTAR Electric | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	37,500	44,000
Long-Term Debt	4,091,800	4,453,500
NSTAR Electric | Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rate Reduction Bonds	0	0
PSNH
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rate Reduction Bonds	410,492	453,702
PSNH | Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	0	0
Long-Term Debt	1,164,600	1,163,800
Rate Reduction Bonds	453,700	496,900
PSNH | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	0	0
Long-Term Debt	970,500	1,220,600
Rate Reduction Bonds	$ 424,700	$ 543,300

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Schedule of Changes in AOCI By Component (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 14,599,844	$ 14,063,566
OCI Before Reclassifications	(4,100)	23,400
Amounts Reclassified from AOCI	7,000	10,700
Net OCI	2,900	34,100
Ending balance	15,473,158	14,599,844
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(42,275)	(76,411)
Ending balance	(39,421)	(42,275)
Qualified Cash Flow Hedging Instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(400)	(1,400)
OCI Before Reclassifications	0	0
Amounts Reclassified from AOCI	0	1,000
Net OCI	0	1,000
Ending balance	(400)	(400)
Unrealized Gains/(Losses) on Marketable Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	400	1,100
OCI Before Reclassifications	(1,600)	(700)
Amounts Reclassified from AOCI	0	0
Net OCI	(1,600)	(700)
Ending balance	(1,200)	400
Defined Benefit Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(42,300)	(76,100)
OCI Before Reclassifications	(2,500)	24,100
Amounts Reclassified from AOCI	7,000	9,700
Net OCI	4,500	33,800
Ending balance	$ (37,800)	$ (42,300)

ACCUMULATED OTHER COMPREHENSI_4

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Equity [Abstract]
Related tax effect recognized in AOCI	$ 1.3	$ 8.3	$ 6

ACCUMULATED OTHER COMPREHENSI_5

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Schedule of Amounts Reclassified From AOCI By Component (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax Effect	$ (453,574)	$ (344,223)	$ (346,186)
Net Income Attributable to Common Shareholders	1,404,875	1,220,527	1,205,167
Defined Benefit Plan Costs:
Total Amounts Reclassified from AOCI, Net of Tax	(7,000)	(10,700)	(7,900)
Qualified Cash Flow Hedging Instruments, Net of Tax | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax Effect	0	700	900
Net Income Attributable to Common Shareholders	0	(1,000)	(1,600)
Amortization of Actuarial Losses
Defined Benefit Plan Costs:
Reclassifications from AOCI	(9,000)	(13,100)	(8,100)
Amortization of Prior Service Cost
Defined Benefit Plan Costs:
Reclassifications from AOCI	(300)	0	(300)
Defined Benefit Plans
Defined Benefit Plan Costs:
Reclassifications from AOCI	(9,300)	(13,100)	(8,400)
Tax Effect	2,300	3,400	2,100
Total Amounts Reclassified from AOCI, Net of Tax	(7,000)	(9,700)	(6,300)
Interest Expense | Qualified Cash Flow Hedging Instruments, Net of Tax | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Qualified Cash Flow Hedging Instruments	$ 0	$ (1,700)	$ (2,500)

DIVIDEND RESTRICTIONS (Details)

DIVIDEND RESTRICTIONS (Details) $ in Millions	Dec. 31, 2022 USD ($)
Schedule of Restrictions on Retained Earnings [Line Items]
Consolidated total debt to total capital ratio (as a percentage)	0.65
Retained earnings subject to restrictions	$ 5,530
CL&P
Schedule of Restrictions on Retained Earnings [Line Items]
Retained earnings subject to restrictions	2,460
NSTAR Electric
Schedule of Restrictions on Retained Earnings [Line Items]
Retained earnings subject to restrictions	2,920
PSNH
Schedule of Restrictions on Retained Earnings [Line Items]
Retained earnings subject to restrictions	$ 572.1

COMMON SHARES - Common Shares A

COMMON SHARES - Common Shares Authorized and Issued (Details) - $ / shares	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Per share par value (in dollars per share)	$ 5	$ 5	$ 5
Authorized (in shares)	380,000,000	380,000,000
Issued (in shares)	359,984,073	357,818,402
CL&P
Class of Stock [Line Items]
Per share par value (in dollars per share)	$ 10	$ 10
Authorized (in shares)	24,500,000	24,500,000
Issued (in shares)	6,035,205	6,035,205
NSTAR Electric
Class of Stock [Line Items]
Per share par value (in dollars per share)	$ 1	$ 1
Authorized (in shares)	100,000,000	100,000,000
Issued (in shares)	200	200
PSNH
Class of Stock [Line Items]
Per share par value (in dollars per share)	$ 1	$ 1
Authorized (in shares)	100,000,000	100,000,000
Issued (in shares)	301	301

COMMON SHARES - Narrative (Deta

COMMON SHARES - Narrative (Details) - USD ($) $ in Thousands				12 Months Ended
	Oct. 03, 2022	May 11, 2022	Dec. 01, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Maximum amount of stock to be issued		$ 1,200,000
Equity offering (in shares)				2,165,671
Consideration received from sale of stock				$ 197,100
Treasury stock (in shares)				11,540,218	13,415,206
Common stock outstanding (in shares)				348,443,855	344,403,196
Issuance of treasury shares for acquisition			$ 38,100	$ 72,133	$ 38,051
Subsidiaries | The Torrington Water Company (TWC)
Class of Stock [Line Items]
Purchase price	$ 72,100
Common Shares
Class of Stock [Line Items]
Common stock outstanding (in shares)				348,443,855	344,403,196	342,954,023	329,880,645
Issuance of treasury shares for acquisition (in shares)			462,517	925,264	462,517

PREFERRED STOCK NOT SUBJECT T_3

PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION - Narrative (Details)	Dec. 31, 2022 $ / shares shares
CL&P
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares) | shares	9,000,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 50
NSTAR Electric
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares) | shares	2,890,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 100

PREFERRED STOCK NOT SUBJECT T_4

PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION - Schedule of Preferred Stock by Class (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Class of Stock [Line Items]
Preferred stock value outstanding	$ 155.6	$ 155.6
CL&P
Class of Stock [Line Items]
Shares outstanding (in shares)	2,324,000	2,324,000
Preferred stock value outstanding	$ 116.2	$ 116.2
CL&P | Series of 1947 Preferred Stock at $1.90
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 1,900,000	$ 1,900,000
Redemption Price Per Share (in dollars per share)	$ 52.50
Shares outstanding (in shares)	163,912	163,912
Preferred stock value outstanding	$ 8.2	$ 8.2
CL&P | Series of 1947 Preferred Stock at $2.00
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 2,000,000	$ 2,000,000
Redemption Price Per Share (in dollars per share)	$ 54
Shares outstanding (in shares)	336,088	336,088
Preferred stock value outstanding	$ 16.8	$ 16.8
CL&P | Series of 1949 Preferred Stock at $2.04
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 2,040,000	$ 2,040,000
Redemption Price Per Share (in dollars per share)	$ 52
Shares outstanding (in shares)	100,000	100,000
Preferred stock value outstanding	$ 5	$ 5
CL&P | Series of 1949 Preferred Stock at $2.20
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 2,200,000	$ 2,200,000
Redemption Price Per Share (in dollars per share)	$ 52.50
Shares outstanding (in shares)	200,000	200,000
Preferred stock value outstanding	$ 10	$ 10
CL&P | Series of 1949 Preferred Stock at 3.90%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	3.90%	3.90%
Redemption Price Per Share (in dollars per share)	$ 50.50
Shares outstanding (in shares)	160,000	160,000
Preferred stock value outstanding	$ 8	$ 8
CL&P | Series E of 1954 Preferred Stock at $2.06
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 2,060,000	$ 2,060,000
Redemption Price Per Share (in dollars per share)	$ 51
Shares outstanding (in shares)	200,000	200,000
Preferred stock value outstanding	$ 10	$ 10
CL&P | Series F of 1955 Preferred Stock at $2.09
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 2,090,000	$ 2,090,000
Redemption Price Per Share (in dollars per share)	$ 51
Shares outstanding (in shares)	100,000	100,000
Preferred stock value outstanding	$ 5	$ 5
CL&P | Series of 1956 Preferred Stock at 4.5%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	4.50%	4.50%
Redemption Price Per Share (in dollars per share)	$ 50.75
Shares outstanding (in shares)	104,000	104,000
Preferred stock value outstanding	$ 5.2	$ 5.2
CL&P | Series of 1958 Preferred Stock at 4.96%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	4.96%	4.96%
Redemption Price Per Share (in dollars per share)	$ 50.50
Shares outstanding (in shares)	100,000	100,000
Preferred stock value outstanding	$ 5	$ 5
CL&P | Series of 1963 Preferred Stock at 4.5%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	4.50%	4.50%
Redemption Price Per Share (in dollars per share)	$ 50.50
Shares outstanding (in shares)	160,000	160,000
Preferred stock value outstanding	$ 8	$ 8
CL&P | Series of 1967 Preferred Stock at 5.28%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	5.28%	5.28%
Redemption Price Per Share (in dollars per share)	$ 51.43
Shares outstanding (in shares)	200,000	200,000
Preferred stock value outstanding	$ 10	$ 10
CL&P | Series G of 1968 Preferred Stock at $3.24
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 3,240,000	$ 3,240,000
Redemption Price Per Share (in dollars per share)	$ 51.84
Shares outstanding (in shares)	300,000	300,000
Preferred stock value outstanding	$ 15	$ 15
CL&P | Series of 1968 Preferred Stock at 6.56%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	6.56%	6.56%
Redemption Price Per Share (in dollars per share)	$ 51.44
Shares outstanding (in shares)	200,000	200,000
Preferred stock value outstanding	$ 10	$ 10
NSTAR Electric
Class of Stock [Line Items]
Shares outstanding (in shares)	430,000	430,000
Preferred stock value outstanding	$ 43	$ 43
NSTAR Electric | Preferred Stock 4.25%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	4.25%	4.25%
Redemption Price Per Share (in dollars per share)	$ 103.625
Shares outstanding (in shares)	180,000	180,000
Preferred stock value outstanding	$ 18	$ 18
NSTAR Electric | Preferred Stock 4.78%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	4.78%	4.78%
Redemption Price Per Share (in dollars per share)	$ 102.80
Shares outstanding (in shares)	250,000	250,000
Preferred stock value outstanding	$ 25	$ 25
Aquarion Water Company | Series of Preferred Stock at 6%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	6%
Redemption Price Per Share (in dollars per share)	$ 100
Shares outstanding (in shares)	23	23
Preferred stock value outstanding	$ 0	$ 0
Fair Value Adjustment | NSTAR Electric
Class of Stock [Line Items]
Preferred stock value outstanding	$ 3.6	$ 3.6

COMMON SHAREHOLDERS' EQUITY A_2

COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Noncontrolling Interest [Line Items]
Net income attributable to noncontrolling interests	$ 1,412,394	$ 1,228,046	$ 1,212,686
Noncontrolling interest - preferred stock of subsidiaries	155,570	155,570
CL&P and NSTAR Electric
Noncontrolling Interest [Line Items]
Net income attributable to noncontrolling interests	$ 7,500	$ 7,500	$ 7,500

REVENUES - Operating Revenues D

REVENUES - Operating Revenues Disaggregated by Revenue Source (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	$ 12,270,200	$ 9,815,000	$ 8,766,500
Alternative Revenue Programs	5,300	41,700	130,000
Other Revenues	13,800	6,400	7,900
Operating Revenues	12,289,336	9,863,085	8,904,430
Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	6,142,700	5,123,600	4,741,500
Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	3,614,200	3,041,400	2,772,900
Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	559,200	499,700	425,600
Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	10,316,100	8,664,700	7,940,000
Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	436,000	453,200	340,900
Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,335,500	661,800	374,100
Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	110,600	114,000	111,500
Amortization of/(Reserve for) Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	72,000	(78,700)
CL&P
Disaggregation of Revenue [Line Items]
Operating Revenues	4,817,744	3,637,412	3,547,527
NSTAR Electric
Disaggregation of Revenue [Line Items]
Operating Revenues	3,583,070	3,056,350	2,941,148
PSNH
Disaggregation of Revenue [Line Items]
Operating Revenues	1,474,799	1,177,248	1,079,095
Operating Segments | Electric Distribution
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	9,409,500	7,404,000	7,038,600
Alternative Revenue Programs	(15,400)	14,700	88,100
Other Revenues	11,200	4,900	5,600
Operating Revenues	9,405,300	7,423,600	7,132,300
Operating Segments | Electric Distribution | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,796,100	3,989,800	3,951,500
Operating Segments | Electric Distribution | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	2,903,300	2,486,100	2,353,400
Operating Segments | Electric Distribution | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	374,900	345,300	327,100
Operating Segments | Electric Distribution | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	8,074,300	6,821,200	6,632,000
Operating Segments | Electric Distribution | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Distribution | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,190,900	575,800	327,300
Operating Segments | Electric Distribution | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	72,300	78,100	79,300
Operating Segments | Electric Distribution | Amortization of/(Reserve for) Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	72,000	(71,100)
Operating Segments | Natural Gas Distribution
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	2,199,500	1,752,300	1,162,900
Alternative Revenue Programs	14,800	37,000	44,700
Other Revenues	1,300	300	1,100
Operating Revenues	2,215,600	1,789,600	1,208,700
Operating Segments | Natural Gas Distribution | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,204,900	1,000,300	644,900
Operating Segments | Natural Gas Distribution | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	648,500	497,600	361,900
Operating Segments | Natural Gas Distribution | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	199,700	167,200	107,400
Operating Segments | Natural Gas Distribution | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	2,053,100	1,665,100	1,114,200
Operating Segments | Natural Gas Distribution | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Natural Gas Distribution | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	140,800	82,100	43,000
Operating Segments | Natural Gas Distribution | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	5,600	5,100	5,700
Operating Segments | Natural Gas Distribution | Amortization of/(Reserve for) Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0
Operating Segments | Electric Transmission
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,715,300	1,759,900	1,570,600
Alternative Revenue Programs	92,700	(126,100)	(35,200)
Other Revenues	700	800	700
Operating Revenues	1,808,700	1,634,600	1,536,100
Operating Segments | Electric Transmission | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Transmission | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Transmission | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Transmission | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Transmission | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,700,500	1,751,300	1,557,300
Operating Segments | Electric Transmission | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Transmission | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	14,100	13,600	13,300
Operating Segments | Electric Transmission | Amortization of/(Reserve for) Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	700	(5,000)
Operating Segments | Water Distribution
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	224,400	209,400	219,600
Alternative Revenue Programs	(2,500)	1,500	(4,700)
Other Revenues	600	400	500
Operating Revenues	222,500	211,300	215,400
Operating Segments | Water Distribution | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	141,700	133,500	145,100
Operating Segments | Water Distribution | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	66,500	62,800	62,400
Operating Segments | Water Distribution | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,700	4,300	4,800
Operating Segments | Water Distribution | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	212,900	200,600	212,300
Operating Segments | Water Distribution | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Water Distribution | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	3,800	3,900	3,800
Operating Segments | Water Distribution | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	8,400	7,500	3,500
Operating Segments | Water Distribution | Amortization of/(Reserve for) Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(700)	(2,600)
Operating Segments | CL&P
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	5,343,200	4,238,900	4,044,700
Alternative Revenue Programs	56,500	(78,900)	(4,200)
Other Revenues	1,800	400	2,200
Operating Segments | CL&P | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	2,397,200	1,994,200	2,011,100
Operating Segments | CL&P | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,067,900	890,600	878,300
Operating Segments | CL&P | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	146,400	131,400	137,500
Operating Segments | CL&P | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	3,611,500	3,016,200	3,026,900
Operating Segments | CL&P | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	755,100	863,300	754,800
Operating Segments | CL&P | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	873,700	408,800	230,100
Operating Segments | CL&P | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	30,200	26,700	32,900
Operating Segments | CL&P | Amortization of/(Reserve for) Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	72,700	(76,100)	0
Operating Segments | NSTAR Electric
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,127,300	3,541,600	3,327,500
Alternative Revenue Programs	700	(15,100)	54,500
Other Revenues	7,200	3,400	3,500
Operating Segments | NSTAR Electric | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,601,800	1,375,800	1,365,800
Operating Segments | NSTAR Electric | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,457,400	1,265,000	1,176,800
Operating Segments | NSTAR Electric | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	135,800	119,100	106,400
Operating Segments | NSTAR Electric | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	3,195,000	2,759,900	2,649,000
Operating Segments | NSTAR Electric | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	670,400	616,300	576,500
Operating Segments | NSTAR Electric | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	215,000	109,200	58,400
Operating Segments | NSTAR Electric | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	46,900	56,200	43,600
Operating Segments | NSTAR Electric | Amortization of/(Reserve for) Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | PSNH
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,659,600	1,387,600	1,241,300
Alternative Revenue Programs	20,100	(17,400)	2,600
Other Revenues	2,900	1,900	600
Operating Segments | PSNH | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	797,100	619,800	574,600
Operating Segments | PSNH | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	380,800	332,200	299,900
Operating Segments | PSNH | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	92,700	94,800	83,200
Operating Segments | PSNH | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,270,600	1,046,800	957,700
Operating Segments | PSNH | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	275,000	271,700	226,000
Operating Segments | PSNH | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	102,200	57,800	38,800
Operating Segments | PSNH | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	11,800	11,300	14,200
Operating Segments | PSNH | Amortization of/(Reserve for) Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	4,600
Other
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,435,500	1,354,000	1,235,900
Alternative Revenue Programs	0	0	0
Other Revenues	0	0	0
Operating Revenues	1,435,500	1,354,000	1,235,900
Other | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	86,600	74,200
Other | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,435,500	1,267,400	1,161,700
Other | Amortization of/(Reserve for) Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0
Eliminations
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(2,714,000)	(2,664,600)	(2,461,100)
Alternative Revenue Programs	(84,300)	114,600	37,100
Other Revenues	0	0	0
Operating Revenues	(2,798,300)	(2,550,000)	(2,424,000)
Eliminations | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Eliminations | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(4,100)	(5,100)	(4,800)
Eliminations | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(20,100)	(17,100)	(13,700)
Eliminations | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(24,200)	(22,200)	(18,500)
Eliminations | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(1,264,500)	(1,384,700)	(1,290,600)
Eliminations | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Eliminations | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(1,425,300)	(1,257,700)	(1,152,000)
Eliminations | Amortization of/(Reserve for) Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0
Consolidations Eliminations | CL&P
Disaggregation of Revenue [Line Items]
Operating Revenues	(583,800)	(523,000)	(495,200)
Consolidations Eliminations | NSTAR Electric
Disaggregation of Revenue [Line Items]
Operating Revenues	(552,100)	(473,500)	(444,400)
Consolidations Eliminations | PSNH
Disaggregation of Revenue [Line Items]
Operating Revenues	$ (207,800)	$ (194,900)	$ (165,400)

REVENUES - Narrative (Details)

REVENUES - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	May 06, 2021	Mar. 31, 2021
Loss Contingencies [Line Items]
Revenue	$ 12,270,200	$ 9,815,000	$ 8,766,500
Loss related to litigation settlement	(72,041)	81,274	0
Lease revenue	$ 4,000	$ 4,800	$ 4,300
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Income, Net	Other Income, Net	Other Income, Net
CL&P
Loss Contingencies [Line Items]
Loss related to litigation settlement	$ (72,041)	$ 81,274	$ 0
Lease revenue	800	800	800
NSTAR Electric
Loss Contingencies [Line Items]
Lease revenue	2,500	3,100	2,700
Amortization of/(Reserve for) Revenues Subject to Refund
Loss Contingencies [Line Items]
Revenue	72,000	(78,700)
Operating Segments | CL&P
Loss Contingencies [Line Items]
Revenue	5,343,200	4,238,900	4,044,700
Operating Segments | NSTAR Electric
Loss Contingencies [Line Items]
Revenue	4,127,300	3,541,600	3,327,500
Operating Segments | Amortization of/(Reserve for) Revenues Subject to Refund | CL&P
Loss Contingencies [Line Items]
Revenue	72,700	(76,100)	0
Operating Segments | Amortization of/(Reserve for) Revenues Subject to Refund | NSTAR Electric
Loss Contingencies [Line Items]
Revenue	0	0	$ 0
Unfavorable Regulatory Action
Loss Contingencies [Line Items]
Loss related to litigation settlement	103,600
Unfavorable Regulatory Action | CL&P
Loss Contingencies [Line Items]
Loss contingency, estimate of possible earnings impact, non-compliance with performance standards				$ 28,400	$ 28,400
Unfavorable Regulatory Action | Operating Segments | Amortization of/(Reserve for) Revenues Subject to Refund | CL&P
Loss Contingencies [Line Items]
Revenue		93,400
Sales | Unfavorable Regulatory Action
Loss Contingencies [Line Items]
Loss related to litigation settlement	$ 65,000
Sales | Unfavorable Regulatory Action | CL&P
Loss Contingencies [Line Items]
Loss related to litigation settlement		$ 65,000

EARNINGS PER SHARE - Narrative

EARNINGS PER SHARE - Narrative (Details) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Antidilutive share awards excluded from the EPS computation (in shares)	0	0	39,560

EARNINGS PER SHARE - Components

EARNINGS PER SHARE - Components of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Income Attributable to Common Shareholders	$ 1,404,875	$ 1,220,527	$ 1,205,167
Weighted Average Common Shares Outstanding:
Basic (in shares)	346,783,444	343,972,926	338,836,147
Dilutive Effect of:
Share-Based Compensation Awards and Other (in shares)	463,324	658,130	738,994
Equity Forward Sale Agreement (in shares)	0	0	271,921
Dilutive Effect (in shares)	463,324	658,130	1,010,915
Diluted (in shares)	347,246,768	344,631,056	339,847,062
Basic EPS (in dollars per share)	$ 4.05	$ 3.55	$ 3.56
Diluted EPS (in dollars per share)	$ 4.05	$ 3.54	$ 3.55

SEGMENT INFORMATION - Narrative

SEGMENT INFORMATION - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) reportableSegment
Segment Reporting Information [Line Items]
Number of reportable segments	1
Yankee Gas, NSTAR Gas and EGMA
Segment Reporting Information [Line Items]
Amount of natural gas transmission purchased | $	$ 77.7
CL&P
Segment Reporting Information [Line Items]
Number of reportable segments	1
NSTAR Electric
Segment Reporting Information [Line Items]
Number of reportable segments	1
PSNH
Segment Reporting Information [Line Items]
Number of reportable segments	1

SEGMENT INFORMATION - Schedule

SEGMENT INFORMATION - Schedule of Segment Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Operating Revenues	$ 12,289,336	$ 9,863,085	$ 8,904,430
Depreciation and Amortization	(1,643,100)	(1,335,000)	(1,159,100)
Other Operating Expenses	(8,448,000)	(6,534,800)	(5,756,600)
Operating Income	2,198,154	1,993,321	1,988,734
Interest Expense	(678,274)	(582,334)	(538,452)
Interest Income	50,500	25,600	4,800
Other Income, Net	295,600	135,700	103,800
Income Tax (Expense)/Benefit	(453,574)	(344,223)	(346,186)
Net Income	1,412,394	1,228,046	1,212,686
Net Income Attributable to Noncontrolling Interests	(7,519)	(7,519)	(7,519)
Net Income Attributable to Common Shareholders	1,404,875	1,220,527	1,205,167
Total Assets (as of)	53,230,900	48,492,144
Cash Flows Used for Investments in Plant	3,441,852	3,175,080	2,942,996
Operating Segments | Electric Distribution
Segment Reporting Information [Line Items]
Operating Revenues	9,405,300	7,423,600	7,132,300
Depreciation and Amortization	(970,400)	(737,800)	(657,000)
Other Operating Expenses	(7,663,700)	(5,970,000)	(5,642,300)
Operating Income	771,200	715,800	833,000
Interest Expense	(253,100)	(236,400)	(216,000)
Interest Income	45,100	20,700	3,200
Other Income, Net	180,400	78,100	58,000
Income Tax (Expense)/Benefit	(146,200)	(103,500)	(129,600)
Net Income	597,400	474,700	548,600
Net Income Attributable to Noncontrolling Interests	(4,600)	(4,600)	(4,600)
Net Income Attributable to Common Shareholders	592,800	470,100	544,000
Total Assets (as of)	27,365,000	25,411,200
Cash Flows Used for Investments in Plant	1,172,600	1,053,300	1,079,000
Operating Segments | Natural Gas Distribution
Segment Reporting Information [Line Items]
Operating Revenues	2,215,600	1,789,600	1,208,700
Depreciation and Amortization	(157,600)	(142,300)	(87,900)
Other Operating Expenses	(1,727,000)	(1,345,400)	(913,800)
Operating Income	331,000	301,900	207,000
Interest Expense	(71,400)	(58,600)	(40,000)
Interest Income	10,200	4,500	900
Other Income, Net	33,600	17,900	3,100
Income Tax (Expense)/Benefit	(69,200)	(60,900)	(36,900)
Net Income	234,200	204,800	134,100
Net Income Attributable to Noncontrolling Interests	0	0	0
Net Income Attributable to Common Shareholders	234,200	204,800	134,100
Total Assets (as of)	8,084,900	7,215,900
Cash Flows Used for Investments in Plant	710,300	721,100	494,400
Operating Segments | Electric Transmission
Segment Reporting Information [Line Items]
Operating Revenues	1,808,700	1,634,600	1,536,100
Depreciation and Amortization	(337,400)	(300,300)	(278,100)
Other Operating Expenses	(548,400)	(496,200)	(470,000)
Operating Income	922,900	838,100	788,000
Interest Expense	(145,500)	(133,200)	(126,800)
Interest Income	500	2,200	4,700
Other Income, Net	37,900	19,800	23,300
Income Tax (Expense)/Benefit	(216,300)	(179,400)	(183,800)
Net Income	599,500	547,500	505,400
Net Income Attributable to Noncontrolling Interests	(2,900)	(2,900)	(2,900)
Net Income Attributable to Common Shareholders	596,600	544,600	502,500
Total Assets (as of)	13,369,500	12,377,800
Cash Flows Used for Investments in Plant	1,144,000	1,024,100	1,004,600
Operating Segments | Water Distribution
Segment Reporting Information [Line Items]
Operating Revenues	222,500	211,300	215,400
Depreciation and Amortization	(50,900)	(46,100)	(44,200)
Other Operating Expenses	(111,800)	(101,400)	(86,600)
Operating Income	59,800	63,800	84,600
Interest Expense	(34,700)	(32,000)	(32,900)
Interest Income	0	0	0
Other Income, Net	8,500	3,300	2,000
Income Tax (Expense)/Benefit	3,200	1,700	(12,500)
Net Income	36,800	36,800	41,200
Net Income Attributable to Noncontrolling Interests	0	0	0
Net Income Attributable to Common Shareholders	36,800	36,800	41,200
Total Assets (as of)	2,783,800	2,551,100
Cash Flows Used for Investments in Plant	154,400	137,200	118,800
Other
Segment Reporting Information [Line Items]
Operating Revenues	1,435,500	1,354,000	1,235,900
Depreciation and Amortization	(132,600)	(113,100)	(93,500)
Other Operating Expenses	(1,189,100)	(1,170,400)	(1,071,900)
Operating Income	113,800	70,500	70,500
Interest Expense	(247,800)	(168,800)	(161,000)
Interest Income	66,300	46,000	37,800
Other Income, Net	1,600,800	1,363,900	1,382,900
Income Tax (Expense)/Benefit	(25,100)	(2,100)	16,600
Net Income	1,508,000	1,309,500	1,346,800
Net Income Attributable to Noncontrolling Interests	0	0	0
Net Income Attributable to Common Shareholders	1,508,000	1,309,500	1,346,800
Total Assets (as of)	26,365,200	22,674,700
Cash Flows Used for Investments in Plant	260,600	239,400	246,200
Eliminations
Segment Reporting Information [Line Items]
Operating Revenues	(2,798,300)	(2,550,000)	(2,424,000)
Depreciation and Amortization	5,800	4,600	1,600
Other Operating Expenses	2,792,000	2,548,600	2,428,000
Operating Income	(500)	3,200	5,600
Interest Expense	74,200	46,600	38,300
Interest Income	(71,600)	(47,800)	(41,800)
Other Income, Net	(1,565,600)	(1,347,300)	(1,365,500)
Income Tax (Expense)/Benefit	0	0	0
Net Income	(1,563,500)	(1,345,300)	(1,363,400)
Net Income Attributable to Noncontrolling Interests	0	0	0
Net Income Attributable to Common Shareholders	(1,563,500)	(1,345,300)	(1,363,400)
Total Assets (as of)	(24,737,500)	(21,738,600)
Cash Flows Used for Investments in Plant	$ 0	$ 0	$ 0

ACQUISITION OF ASSETS OF COLU_3

ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS - Narrative (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
	Oct. 09, 2020	Dec. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Operating revenues					$ 154.8
Pre-tax income					13.9
TSA
Business Acquisition [Line Items]
TSA and pre-TSA costs			$ 7.9	$ 21.4	15.9
Energy efficiency expense		$ 2
CMA
Business Acquisition [Line Items]
Consideration transferred	$ 1,100
Target working capital amount	$ 68.6
Operating revenues					$ 9,273

ACQUISITION OF ASSETS OF COLU_4

ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS - Schedule of Pro Forma Information (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares
Business Acquisition [Line Items]
Operating Revenues	$ 154.8
CMA
Business Acquisition [Line Items]
Operating Revenues	9,273
Net Income Attributable to Common Shareholders	$ 1,265
Basic EPS (in dollars per share) | $ / shares	$ 3.73
Diluted EPS (in dollars per share) | $ / shares	$ 3.72

GOODWILL - Narrative (Details)

GOODWILL - Narrative (Details) - USD ($)			12 Months Ended
	Oct. 03, 2022	Oct. 01, 2022	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Line Items]
Impairment loss		$ 0
CMA
Goodwill [Line Items]
Goodwill acquired			$ 51,900,000
CMA Measurement Period Adjustments				$ 9,600,000
The Torrington Water Company (TWC)
Goodwill [Line Items]
Goodwill acquired			44,800,000
New England Service Company (NESC)
Goodwill [Line Items]
Goodwill acquired				21,700,000
CMA Measurement Period Adjustments			500,000
Water Distribution | CMA
Goodwill [Line Items]
CMA Measurement Period Adjustments			9,600,000	0
Water Distribution | The Torrington Water Company (TWC)
Goodwill [Line Items]
Goodwill acquired	$ 44,800,000		44,800,000
Water Distribution | New England Service Company (NESC)
Goodwill [Line Items]
Goodwill acquired			22,200,000	$ 21,700,000
CMA Measurement Period Adjustments			$ 500,000

GOODWILL - Summary of Goodwill

GOODWILL - Summary of Goodwill by Reportable Segment (Details) - USD ($) $ in Thousands		12 Months Ended
	Oct. 03, 2022	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Roll Forward]
Beginning Balance		$ 4,477,269	$ 4,446,000
Ending Balance		4,522,632	4,477,269
The Torrington Water Company (TWC)
Goodwill [Roll Forward]
Goodwill acquired		44,800
New England Service Company (NESC)
Goodwill [Roll Forward]
Measurement Period Adjustments		500
Goodwill acquired			21,700
CMA
Goodwill [Roll Forward]
Measurement Period Adjustments			9,600
Goodwill acquired		51,900
Electric Distribution
Goodwill [Roll Forward]
Beginning Balance		2,543,600	2,543,600
Ending Balance		2,543,600	2,543,600
Electric Distribution | The Torrington Water Company (TWC)
Goodwill [Roll Forward]
Goodwill acquired		0
Electric Distribution | New England Service Company (NESC)
Goodwill [Roll Forward]
Measurement Period Adjustments		0
Goodwill acquired			0
Electric Distribution | CMA
Goodwill [Roll Forward]
Measurement Period Adjustments			0
Electric Transmission
Goodwill [Roll Forward]
Beginning Balance		576,800	576,800
Ending Balance		576,800	576,800
Electric Transmission | The Torrington Water Company (TWC)
Goodwill [Roll Forward]
Goodwill acquired		0
Electric Transmission | New England Service Company (NESC)
Goodwill [Roll Forward]
Measurement Period Adjustments		0
Goodwill acquired			0
Electric Transmission | CMA
Goodwill [Roll Forward]
Measurement Period Adjustments			0
Natural Gas Distribution
Goodwill [Roll Forward]
Beginning Balance		451,000	441,400
Ending Balance		451,000	451,000
Natural Gas Distribution | The Torrington Water Company (TWC)
Goodwill [Roll Forward]
Goodwill acquired		0
Natural Gas Distribution | New England Service Company (NESC)
Goodwill [Roll Forward]
Measurement Period Adjustments		0
Goodwill acquired			0
Natural Gas Distribution | CMA
Goodwill [Roll Forward]
Measurement Period Adjustments			9,600
Water Distribution
Goodwill [Roll Forward]
Beginning Balance		905,900	884,200
Ending Balance		951,200	905,900
Water Distribution | The Torrington Water Company (TWC)
Goodwill [Roll Forward]
Goodwill acquired	$ 44,800	44,800
Water Distribution | New England Service Company (NESC)
Goodwill [Roll Forward]
Measurement Period Adjustments		500
Goodwill acquired		22,200	21,700
Water Distribution | CMA
Goodwill [Roll Forward]
Measurement Period Adjustments		$ 9,600	$ 0

SCHEDULE I - FINANCIAL INFORM_2

SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - BALANCE SHEET (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current Assets:
Cash	$ 47,597	$ 66,773
Prepayments and Other Current Assets	382,603	369,759
Total Current Assets	4,223,198	3,270,120
Deferred Debits and Other Assets:
Investments in Subsidiary Companies, at Equity	2,176,080	1,436,293
Goodwill	4,522,632	4,477,269	$ 4,446,000
Other Long-Term Assets	541,344	611,769
Total Deferred Debits and Other Assets	12,894,882	11,844,374
Total Assets (as of)	53,230,900	48,492,144
Current Liabilities:
Notes Payable	1,442,200	1,505,450
Long-Term Debt – Current Portion	1,320,129	1,193,097
Other Current Liabilities	989,053	830,620
Total Current Liabilities	6,799,283	5,847,039
Liabilities, Noncurrent [Abstract]
Other Long-Term Liabilities	888,081	971,080
Total Deferred Credits and Other Liabilities	10,668,403	10,412,412
Capitalization:
Long-Term Debt	19,723,994	17,023,577
Common Shareholders' Equity:
Capital Surplus, Paid in	8,401,731	8,098,514
Retained Earnings	5,527,153	5,005,391
Accumulated Other Comprehensive Loss	(39,421)	(42,275)
Treasury Stock	(216,225)	(250,878)
Stockholders' equity	15,473,158	14,599,844	$ 14,063,566	$ 12,629,994
Total Liabilities and Capitalization	53,230,900	48,492,144
Eversource
Current Assets:
Cash	971	175
Accounts Receivable from Subsidiaries	53,338	43,403
Notes Receivable from Subsidiaries	1,074,800	1,245,900
Prepayments and Other Current Assets	23,597	11,974
Total Current Assets	1,152,706	1,301,452
Deferred Debits and Other Assets:
Investments in Subsidiary Companies, at Equity	18,379,840	16,108,190
Notes Receivable from Subsidiaries	1,896,500	1,001,000
Accumulated Deferred Income Taxes	0	17,409
Goodwill	3,852,524	3,852,524
Other Long-Term Assets	108,867	101,710
Total Deferred Debits and Other Assets	24,237,731	21,080,833
Total Assets (as of)	25,390,437	22,382,285
Current Liabilities:
Notes Payable	1,442,200	1,342,950
Long-Term Debt – Current Portion	1,207,047	767,681
Accounts Payable to Subsidiaries	33,530	37,609
Other Current Liabilities	112,807	87,745
Total Current Liabilities	2,795,584	2,235,985
Liabilities, Noncurrent [Abstract]
Accumulated Deferred Income Taxes	8,498	0
Other Long-Term Liabilities	140,393	150,616
Total Deferred Credits and Other Liabilities	148,891	150,616
Capitalization:
Long-Term Debt	6,972,804	5,395,840
Common Shareholders' Equity:
Common Shares	1,799,920	1,789,092
Capital Surplus, Paid in	8,401,731	8,098,514
Retained Earnings	5,527,153	5,005,391
Accumulated Other Comprehensive Loss	(39,421)	(42,275)
Treasury Stock	(216,225)	(250,878)
Stockholders' equity	15,473,158	14,599,844
Total Liabilities and Capitalization	$ 25,390,437	$ 22,382,285

SCHEDULE I - FINANCIAL INFORM_3

SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENTS OF INCOME (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Income Statements, Captions [Line Items]
Operating Revenues	$ 12,289,336	$ 9,863,085	$ 8,904,430
Operating Expenses:
Other	1,865,328	1,739,685	1,480,252
Operating Income (Loss)	2,198,154	1,993,321	1,988,734
Interest Expense	678,274	582,334	538,452
Other Income, Net:
Equity in Earnings of Subsidiaries	22,900	14,200	14,200
Other Income, Net	346,088	161,282	108,590
Income Before Income Tax Expense	1,865,968	1,572,269	1,558,872
Income Tax Benefit	453,574	344,223	346,186
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Basic Earnings Per Common Share (in dollars per share)	$ 4.05	$ 3.55	$ 3.56
Diluted Earnings Per Common Share (in dollars per share)	$ 4.05	$ 3.54	$ 3.55
Weighted Average Common Shares Outstanding:
Basic (in shares)	346,783,444	343,972,926	338,836,147
Diluted (in shares)	347,246,768	344,631,056	339,847,062
Eversource
Condensed Income Statements, Captions [Line Items]
Operating Revenues	$ 0	$ 0	$ 0
Operating Expenses:
Other	26,708	43,048	28,645
Operating Income (Loss)	(26,708)	(43,048)	(28,645)
Interest Expense	237,773	163,613	160,887
Other Income, Net:
Equity in Earnings of Subsidiaries	1,565,474	1,345,199	1,309,630
Other, Net	79,383	47,802	38,546
Other Income, Net	1,644,857	1,393,001	1,348,176
Income Before Income Tax Expense	1,380,376	1,186,340	1,158,644
Income Tax Benefit	(24,499)	(34,187)	(46,523)
Net Income	$ 1,404,875	$ 1,220,527	$ 1,205,167
Basic Earnings Per Common Share (in dollars per share)	$ 4.05	$ 3.55	$ 3.56
Diluted Earnings Per Common Share (in dollars per share)	$ 4.05	$ 3.54	$ 3.55
Weighted Average Common Shares Outstanding:
Basic (in shares)	346,783,444	343,972,926	338,836,147
Diluted (in shares)	347,246,768	344,631,056	339,847,062

SCHEDULE I - FINANCIAL INFORM_4

SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENTS OF COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Statement of Income Captions [Line Items]
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	20	972	1,596
Changes in Unrealized (Losses)/Gains on Marketable Securities	(1,636)	(671)	342
Changes in Funded Status of Pension, SERP and PBOP Benefit Plans	4,470	33,835	(13,290)
Other Comprehensive Income/(Loss), Net of Tax	2,854	34,136	(11,352)
Comprehensive Income	1,407,729	1,254,663	1,193,815
Eversource
Condensed Statement of Income Captions [Line Items]
Net Income	1,404,875	1,220,527	1,205,167
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	20	972	1,596
Changes in Unrealized (Losses)/Gains on Marketable Securities	(1,636)	(671)	342
Changes in Funded Status of Pension, SERP and PBOP Benefit Plans	4,470	33,835	(13,290)
Other Comprehensive Income/(Loss), Net of Tax	2,854	34,136	(11,352)
Comprehensive Income	$ 1,407,729	$ 1,254,663	$ 1,193,815

SCHEDULE I - FINANCIAL INFORM_5

SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENT OF CASH FLOW (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Equity in Earnings of Subsidiaries	(22,900)	(14,200)	(14,200)
Deferred Income Taxes	346,779	347,056	257,154
Other	(39,192)	(64,640)	(25,957)
Receivables and Unbilled Revenues, Net	(470,593)	(135,505)	(351,843)
Taxes Receivable/Accrued, Net	18,358	(110,621)	43,819
Other Current Assets and Liabilities, Net	(45,583)	3,710	(24,995)
Net Cash Flows Provided by Operating Activities	2,401,293	1,962,600	1,682,572
Investing Activities:
Other Investing Activities	20,420	22,178	23,809
Net Cash Flows Used in Investing Activities	(4,130,490)	(3,447,374)	(4,129,275)
Financing Activities:
Issuance of Common Shares, Net of Issuance Costs	197,058	0	928,992
Cash Dividends on Common Shares	(860,033)	(805,439)	(744,665)
Issuance of Long-Term Debt	4,045,000	3,230,000	2,760,000
Retirement of Long-Term Debt	(1,175,000)	(1,142,500)	(327,236)
Other Financing Activities	(48,185)	(46,625)	14,273
Net Cash Flows Provided by Financing Activities	2,029,941	1,440,832	2,594,590
Net Increase/(Decrease) in Cash, Cash Equivalents and Restricted Cash	300,744	(43,942)	147,887
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	221,008	264,950	117,063
Cash, Cash Equivalents and Restricted Cash - End of Year	521,752	221,008	264,950
Cash Paid/(Received) During the Year for:
Interest	636,200	568,700	518,000
Income Taxes	77,900	121,600	48,900
Eversource
Operating Activities:
Net Income	1,404,875	1,220,527	1,205,167
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Equity in Earnings of Subsidiaries	(1,565,474)	(1,345,199)	(1,309,630)
Cash Dividends Received from Subsidiaries	855,600	1,037,100	485,800
Deferred Income Taxes	25,823	20,293	(4,667)
Other	26,455	36,910	39,940
Receivables and Unbilled Revenues, Net	(9,935)	(3,758)	(14,575)
Taxes Receivable/Accrued, Net	(21,627)	(19,455)	35,300
Accounts Payable to Subsidiaries	(4,079)	19,185	14,091
Other Current Assets and Liabilities, Net	35,090	8,144	21,284
Net Cash Flows Provided by Operating Activities	746,728	973,747	472,710
Investing Activities:
Capital Contributions to Subsidiaries	(1,499,300)	(1,033,000)	(1,899,340)
Return of Capital from Subsidiaries	12,000	178,800	80,000
Increase in Notes Receivable from Subsidiaries	(724,400)	(140,200)	(264,300)
Other Investing Activities	(1,289)	(3,196)	(367)
Net Cash Flows Used in Investing Activities	(2,212,989)	(997,596)	(2,084,007)
Financing Activities:
Issuance of Common Shares, Net of Issuance Costs	197,058	0	928,992
Cash Dividends on Common Shares	(860,033)	(805,439)	(744,665)
Issuance of Long-Term Debt	2,800,000	1,000,000	1,550,000
Retirement of Long-Term Debt	(750,000)	(450,000)	0
Increase (Decrease) in Notes Payable to Eversource Parent	99,250	288,625	(170,545)
Other Financing Activities	(19,193)	(9,545)	46,480
Net Cash Flows Provided by Financing Activities	1,467,082	23,641	1,610,262
Net Increase/(Decrease) in Cash, Cash Equivalents and Restricted Cash	821	(208)	(1,035)
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	226	434	1,469
Cash, Cash Equivalents and Restricted Cash - End of Year	1,047	226	434
Cash Paid/(Received) During the Year for:
Interest	215,053	164,568	140,694
Income Taxes	$ (20,992)	$ (51,277)	$ (43,158)

SCHEDULE II - VALUATION AND Q_2

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Increase due to CMA acquisition			$ 24,200
Allowance for uncollectible accounts for late fees and other receivable amounts	$ 486,297	$ 417,406	358,900	$ 224,800
Restatement Adjustment
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Allowance for uncollectible accounts for late fees and other receivable amounts			23,800	23,800
CL&P
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Increase due to CMA acquisition			0
Allowance for uncollectible accounts for late fees and other receivable amounts	225,320	181,319	157,400	97,300
CL&P | Restatement Adjustment
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Allowance for uncollectible accounts for late fees and other receivable amounts			22,200	22,200
NSTAR Electric
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Increase due to CMA acquisition			0
Allowance for uncollectible accounts for late fees and other receivable amounts	94,958	97,005	91,600	75,400
NSTAR Electric | Restatement Adjustment
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Allowance for uncollectible accounts for late fees and other receivable amounts			(1,300)	(1,300)
PSNH
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Increase due to CMA acquisition			0
Allowance for uncollectible accounts for late fees and other receivable amounts	29,236	24,331	17,200	10,500
PSNH | Restatement Adjustment
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Allowance for uncollectible accounts for late fees and other receivable amounts			300	$ 300
Allowance for Doubtful Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	417,406	358,851	224,821
Additions, Charged to Costs and Expense	61,876	60,886	53,461
Additions, Charged to Other Accounts	112,533	110,572	145,005
Deductions	105,518	112,903	64,436
Balance at end of period	486,297	417,406	358,851
Allowance for Doubtful Accounts | CL&P
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	181,319	157,447	97,348
Additions, Charged to Costs and Expense	15,578	13,495	12,882
Additions, Charged to Other Accounts	59,485	57,779	71,223
Deductions	31,062	47,402	24,006
Balance at end of period	225,320	181,319	157,447
Allowance for Doubtful Accounts | NSTAR Electric
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	97,005	91,583	75,406
Additions, Charged to Costs and Expense	21,550	16,649	15,293
Additions, Charged to Other Accounts	12,412	20,064	23,424
Deductions	36,009	31,291	22,540
Balance at end of period	94,958	97,005	91,583
Allowance for Doubtful Accounts | PSNH
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	24,331	17,157	10,497
Additions, Charged to Costs and Expense	9,211	13,113	5,164
Additions, Charged to Other Accounts	2,539	3,135	7,692
Deductions	6,845	9,074	6,196
Balance at end of period	$ 29,236	$ 24,331	$ 17,157

Uncategorized Items - es-202212

Label	Element	Value
Accounting Standards Update [Extensible Enumeration]	us-gaap_AccountingStandardsUpdateExtensibleList	Accounting Standards Update 2016-13 [Member]
Public Service Company Of New Hampshire (PSNH) [Member]
Accounting Standards Update [Extensible Enumeration]	us-gaap_AccountingStandardsUpdateExtensibleList	Accounting Standards Update 2016-13 [Member]
NSTAR Electric Company [Member]
Accounting Standards Update [Extensible Enumeration]	us-gaap_AccountingStandardsUpdateExtensibleList	Accounting Standards Update 2016-13 [Member]
The Connecticut Light And Power Company [Member]
Accounting Standards Update [Extensible Enumeration]	us-gaap_AccountingStandardsUpdateExtensibleList	Accounting Standards Update 2016-13 [Member]