NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Current Assets:
Receivables, Net (net of allowance for uncollectible accounts)	$ 1,656,090	$ 1,651,325
Unbilled Revenues	162,932	242,169
Materials, Supplies and REC Inventory	528,111	594,568
Regulatory Assets	1,831,224	2,189,660
Prepayments and Other Current Assets	352,589	315,368
Total Current Assets	4,858,758	5,076,073
Property, Plant and Equipment, Net	43,044,113	40,986,578
Deferred Debits and Other Assets:
Regulatory Assets	4,838,923	4,880,974
Prepaid Pension and PBOP	1,434,847	1,336,633
Other Long-Term Assets	942,146	811,521
Total Deferred Debits and Other Assets	13,799,704	13,531,878
Total Assets	61,702,575	59,594,529
Current Liabilities:
Notes Payable	1,517,500	2,042,793
Long-Term Debt – Current Portion	1,140,007	1,003,150
Accounts Payable	1,483,634	1,736,880
Regulatory Liabilities	1,064,050	632,282
Other Current Liabilities	676,136	853,491
Total Current Liabilities	6,798,288	6,720,957
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	5,546,906	5,411,206
Regulatory Liabilities	4,114,348	4,032,564
Other Long-Term Liabilities	824,988	773,999
Total Deferred Credits and Other Liabilities	11,585,182	11,652,918
Long-Term Debt	26,854,425	25,701,627
Preferred Stock Not Subject to Mandatory Redemption	155,568	155,568
Common Shareholders' Equity:
Capital Surplus, Paid In	9,916,324	9,428,905
Retained Earnings	4,366,085	3,929,141
Accumulated Other Comprehensive Loss	(23,075)	(26,472)
Common Shareholders' Equity	16,028,250	15,039,387
Commitments and Contingencies (Note 9)
Total Liabilities and Capitalization	61,702,575	59,594,529
NSTAR Electric Company
Current Assets:
Cash and Cash Equivalents	18,558	911
Unbilled Revenues	48,283	59,079
Materials, Supplies and REC Inventory	189,111	220,621
Regulatory Assets	912,343	902,770
Prepayments and Other Current Assets	55,051	72,986
Total Current Assets	2,100,766	1,953,851
Property, Plant and Equipment, Net	14,910,449	14,037,828
Deferred Debits and Other Assets:
Regulatory Assets	1,117,130	1,204,337
Prepaid Pension and PBOP	766,906	724,661
Other Long-Term Assets	253,297	154,571
Total Deferred Debits and Other Assets	2,137,333	2,083,569
Total Assets	19,148,548	18,075,248
Current Liabilities:
Notes Payable	479,000	504,782
Long-Term Debt – Current Portion	244,597	250,000
Obligations to Third Party Suppliers	158,615	163,711
Regulatory Liabilities	543,194	436,312
Other Current Liabilities	157,570	202,197
Total Current Liabilities	2,233,984	2,245,542
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	2,050,260	2,005,439
Regulatory Liabilities	1,670,310	1,643,079
Other Long-Term Liabilities	398,444	377,462
Total Deferred Credits and Other Liabilities	4,119,014	4,025,980
Long-Term Debt	5,644,983	4,844,920
Preferred Stock Not Subject to Mandatory Redemption	43,000	43,000
Common Shareholders' Equity:
Common Stock	0	0
Capital Surplus, Paid In	3,888,842	3,788,842
Retained Earnings	3,218,867	3,127,105
Accumulated Other Comprehensive Loss	(142)	(141)
Common Shareholders' Equity	7,107,567	6,915,806
Commitments and Contingencies (Note 9)
Total Liabilities and Capitalization	19,148,548	18,075,248
NSTAR Electric Company | Nonrelated Party
Current Assets:
Receivables, Net (net of allowance for uncollectible accounts)	665,964	614,563
Current Liabilities:
Accounts Payable	487,385	534,868
NSTAR Electric Company | Related Party
Current Assets:
Receivables, Net (net of allowance for uncollectible accounts)	211,456	82,921
Current Liabilities:
Accounts Payable	$ 163,623	$ 153,672