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
Balance (in shares) at Dec. 31, 2020		342,954,023					6,035,205
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	368,023			368,023		98,398			98,398
Dividends on Preferred Stock	(1,880)			(1,880)		(1,390)			(1,390)
Dividends on Common Stock	(206,913)			(206,913)		(70,100)			(70,100)
Other Comprehensive Loss	1,188				1,188	(32)				(32)
Balance (in shares) at Mar. 31, 2021		343,434,298					6,035,205
Balance at Mar. 31, 2021	$ 14,233,420	$ 1,789,092	8,016,118	4,772,431	(75,223)	5,071,662	$ 60,352	2,810,765	2,200,275	270
Balance (in shares) at Dec. 31, 2021	344,403,196	344,403,196					6,035,205
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	445,326			445,326		152,977			152,977
Dividends on Preferred Stock	(1,880)			(1,880)		(1,390)			(1,390)
Dividends on Common Stock	(219,768)			(219,768)		(73,100)			(73,100)
Capital Contributions from Eversource Parent						100,000		100,000
Other Comprehensive Loss	$ 704				704	(35)				(35)
Balance (in shares) at Mar. 31, 2022	344,850,272	344,850,272					6,035,205
Balance at Mar. 31, 2022	$ 14,836,690	$ 1,789,092	$ 8,102,618	$ 5,229,069	$ (41,571)	$ 5,477,953	$ 60,352	$ 3,110,765	$ 2,306,620	$ 216