CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net Income	$ 1,040,519	$ 995,515	$ 949,821
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	1,756	1,974	2,137
Changes in Unrealized (Losses)/Gains on Marketable Securities	(547)	(350)	2,294
Change in Funded Status of Pension, SERP and PBOP Benefit Plans	5,194	(2,745)	(2,869)
Other Comprehensive Income/(Loss), Net of Tax	6,403	(1,121)	1,562
Comprehensive Income Attributable to Noncontrolling Interests	(7,519)	(7,519)	(7,519)
Comprehensive Income	1,039,403	986,875	943,864
The Connecticut Light And Power Company
Net Income	377,717	376,726	334,254
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	51	334	444
Changes in Unrealized (Losses)/Gains on Marketable Securities	(19)	(12)	79
Other Comprehensive Income/(Loss), Net of Tax	32	322	523
Comprehensive Income	377,749	377,048	334,777
NSTAR Electric Company
Net Income	383,090	374,726	350,777
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	437	438	437
Changes in Unrealized (Losses)/Gains on Marketable Securities	(5)	(3)	22
Change in Funded Status of Pension, SERP and PBOP Benefit Plans	13	(264)	(177)
Other Comprehensive Income/(Loss), Net of Tax	445	171	282
Comprehensive Income	383,535	374,897	351,059
Public Service Company Of New Hampshire
Net Income	115,876	135,996	131,985
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	1,104	1,162	1,162
Changes in Unrealized (Losses)/Gains on Marketable Securities	(33)	(21)	136
Other Comprehensive Income/(Loss), Net of Tax	1,071	1,141	1,298
Comprehensive Income	$ 116,947	$ 137,137	$ 133,283