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