THE CONNECTICUT LIGHT AND POWER COMPANY CONDENSED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Thousands	Total	Common Stock	Capital Surplus, Paid In	Retained Earnings	Accumulated Other Comprehensive Loss	The Connecticut Light and Power Company	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 Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2023		349,540,266					6,035,205
Balance as of Beginning of Period at Dec. 31, 2023	$ 14,173,892	$ 1,799,920	$ 8,460,876	$ 4,142,515	$ (33,737)	$ 6,090,670	$ 60,352	$ 3,384,265	$ 2,645,868	$ 185
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						138,353			138,353
Dividends on Preferred Stock	(1,880)			(1,880)		(1,390)			(1,390)
Dividends on Common Stock	(250,770)			(250,770)		(82,500)			(82,500)
Capital Contributions from Eversource Parent						100,000		100,000
Other Comprehensive Income						(7)				(7)
Ending balance (in shares) at Mar. 31, 2024		351,379,414					6,035,205
Balance as of End of Period at Mar. 31, 2024	14,543,588	$ 1,806,385	8,537,591	4,413,593	(28,534)	6,245,126	$ 60,352	3,484,265	2,700,331	178
Beginning balance (in shares) at Dec. 31, 2023		349,540,266					6,035,205
Balance as of Beginning of Period at Dec. 31, 2023	14,173,892	$ 1,799,920	8,460,876	4,142,515	(33,737)	6,090,670	$ 60,352	3,384,265	2,645,868	185
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						401,844
Other Comprehensive Income						(20)
Ending balance (in shares) at Sep. 30, 2024		363,891,973					6,035,205
Balance as of End of Period at Sep. 30, 2024	15,044,424	$ 1,866,385	9,263,434	4,118,654	(28,205)	6,540,724	$ 60,352	3,684,265	2,795,942	165
Beginning balance (in shares) at Mar. 31, 2024		351,379,414					6,035,205
Balance as of Beginning of Period at Mar. 31, 2024	14,543,588	$ 1,806,385	8,537,591	4,413,593	(28,534)	6,245,126	$ 60,352	3,484,265	2,700,331	178
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						131,601			131,601
Dividends on Preferred Stock	(1,880)			(1,880)		(1,390)			(1,390)
Dividends on Common Stock	(252,104)			(252,104)
Capital Contributions from Eversource Parent						100,000		100,000
Other Comprehensive Income						(6)				(6)
Ending balance (in shares) at Jun. 30, 2024		354,566,071					6,035,205
Balance as of End of Period at Jun. 30, 2024	14,818,713	$ 1,820,954	8,710,844	4,496,830	(29,581)	6,475,331	$ 60,352	3,584,265	2,830,542	172
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						131,890			131,890
Dividends on Preferred Stock	(1,880)			(1,880)		(1,390)			(1,390)
Dividends on Common Stock	(260,119)			(260,119)		(165,100)			(165,100)
Capital Contributions from Eversource Parent						100,000		100,000
Other Comprehensive Income						(7)				(7)
Ending balance (in shares) at Sep. 30, 2024		363,891,973					6,035,205
Balance as of End of Period at Sep. 30, 2024	$ 15,044,424	$ 1,866,385	9,263,434	4,118,654	(28,205)	6,540,724	$ 60,352	3,684,265	2,795,942	165
Beginning balance (in shares) at Dec. 31, 2024	366,608,052	366,608,052					6,035,205
Balance as of Beginning of Period at Dec. 31, 2024	$ 15,039,387	$ 1,878,622	9,428,905	3,929,141	(26,472)	6,563,882	$ 60,352	3,684,265	2,819,107	158
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						156,236			156,236
Dividends on Preferred Stock	(1,880)			(1,880)		(1,390)			(1,390)
Dividends on Common Stock	(276,229)			(276,229)		(247,000)			(247,000)
Other Comprehensive Income						(6)				(6)
Ending balance (in shares) at Mar. 31, 2025		367,307,083					6,035,205
Balance as of End of Period at Mar. 31, 2025	$ 15,341,257	$ 1,878,622	9,440,596	4,203,700	(23,949)	6,471,722	$ 60,352	3,684,265	2,726,953	152
Beginning balance (in shares) at Dec. 31, 2024	366,608,052	366,608,052					6,035,205
Balance as of Beginning of Period at Dec. 31, 2024	$ 15,039,387	$ 1,878,622	9,428,905	3,929,141	(26,472)	6,563,882	$ 60,352	3,684,265	2,819,107	158
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						429,511
Other Comprehensive Income						(19)
Ending balance (in shares) at Sep. 30, 2025	375,096,584	375,096,584					6,035,205
Balance as of End of Period at Sep. 30, 2025	$ 16,028,250	$ 1,914,273	9,916,324	4,366,085	(23,075)	6,559,204	$ 60,352	3,684,265	2,814,448	139
Beginning balance (in shares) at Mar. 31, 2025		367,307,083					6,035,205
Balance as of Beginning of Period at Mar. 31, 2025	15,341,257	$ 1,878,622	9,440,596	4,203,700	(23,949)	6,471,722	$ 60,352	3,684,265	2,726,953	152
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						138,641			138,641
Dividends on Preferred Stock	(1,880)			(1,880)		(1,390)			(1,390)
Dividends on Common Stock	(276,513)			(276,513)		(83,000)			(83,000)
Other Comprehensive Income						(7)				(7)
Ending balance (in shares) at Jun. 30, 2025		371,038,611					6,035,205
Balance as of End of Period at Jun. 30, 2025	15,665,791	$ 1,895,516	9,665,374	4,279,915	(23,912)	6,525,966	$ 60,352	3,684,265	2,781,204	145
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						134,634			134,634
Dividends on Preferred Stock	(1,880)			(1,880)		(1,390)			(1,390)
Dividends on Common Stock	$ (281,379)			(281,379)		(100,000)			(100,000)
Other Comprehensive Income						(6)				(6)
Ending balance (in shares) at Sep. 30, 2025	375,096,584	375,096,584					6,035,205
Balance as of End of Period at Sep. 30, 2025	$ 16,028,250	$ 1,914,273	$ 9,916,324	$ 4,366,085	$ (23,075)	$ 6,559,204	$ 60,352	$ 3,684,265	$ 2,814,448	$ 139