THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Thousands	Total	Common Stock	Capital Surplus, Paid In	Retained Earnings	Accumulated Other Comprehensive Income (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 Income (Loss)
Beginning balance (in shares) at Dec. 31, 2020		342,954,023					6,035,205
Beginning 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 (Loss)/Income	1,228,000					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						200,000		200,000
Other Comprehensive (Loss)/Income, Net of Tax						(51)				(51)
Ending balance (in shares) at Dec. 31, 2021		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 (Loss)/Income	1,412,400					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	210,000					250,000		250,000
Other Comprehensive (Loss)/Income, Net of Tax	$ 2,900					(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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss)/Income	(434,700)					518,733			518,733
Dividends on Preferred Stock	(7,519)			(7,519)		(5,559)			(5,559)
Dividends on Common Stock	(942,398)			(942,398)		(330,400)			(330,400)
Capital Contributions from Eversource Parent						123,500		123,500
Other Comprehensive (Loss)/Income, Net of Tax	$ 5,700					16				16
Ending balance (in shares) at Dec. 31, 2023	349,540,266	349,540,266					6,035,205
Ending balance 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