NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net Income	$ 1,412,394	$ 1,228,046	$ 1,212,686
Other Comprehensive Income/(Loss), Net of Tax:
Changes in Funded Status of SERP Benefit Plan	4,470	33,835	(13,290)
Qualified Cash Flow Hedging Instruments	20	972	1,596
Changes in Unrealized (Losses)/Gains on Marketable Securities	(1,636)	(671)	342
Other Comprehensive Income/(Loss), Net of Tax	2,854	34,136	(11,352)
Comprehensive Income Attributable to Common Shareholders	1,407,729	1,254,663	1,193,815
NSTAR Electric Company
Net Income	492,428	476,569	445,001
Other Comprehensive Income/(Loss), Net of Tax:
Changes in Funded Status of SERP Benefit Plan	(221)	(100)	(286)
Qualified Cash Flow Hedging Instruments	20	298	437
Changes in Unrealized (Losses)/Gains on Marketable Securities	(16)	(6)	3
Other Comprehensive Income/(Loss), Net of Tax	(217)	192	154
Comprehensive Income Attributable to Common Shareholders	$ 492,211	$ 476,761	$ 445,155