CONSOLIDATED STATEMENT OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating Activities:
Net Income	$ 603,576	$ 614,413
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Depreciation	456,224	463,635
Deferred Income Tax Expense (Benefit)	64,755	334,225
Pension, SERP and PBOP Expense	74,296	146,803
Pension and PBOP Contributions	(74,681)	(338,301)
Regulatory Over/(Under) Recoveries, Net	290,111	66,239
Amortization of Regulatory Assets/(Liabilities), Net	31,826	178,668
Amortization of Rate Reduction Bonds	0	42,581
Proceeds from DOE Damages Claim, Net	132,138
Other Noncash Income (Expense)	(17,096)	3,158
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(66,463)	(98,432)
Increase Decrease in Fuel, Materials and Supplies	(27,147)	(13,134)
Taxes Receivable/(Accrued)	26,533	(28,609)
Accounts Payable	(69,448)	(112,512)
Other Current Assets and Liabilities	(20,607)	(81,766)
Net Cash Flows Provided by Operating Activities	1,404,017	1,176,968
Investing Activities:
Investments in Property, Plant and Equipment	(1,117,493)	(1,073,759)
Proceeds from Sales of Marketable Securities	388,352	487,729
Purchases of Marketable Securities	(389,406)	(541,070)
Decrease In Restricted Cash	0	69,259
Other Investing Activities	(4,669)	(1,137)
Net Cash Flows Used in Investing Activities	(1,123,216)	(1,058,978)
Financing Activities:
Cash Dividends on Common Stock	(356,080)	(341,720)
Cash Dividends on Preferred Stock	(5,639)	(5,802)
Increase/(Decrease) in Short-Term Debt	6,000	(172,000)
Issuance of Long-Term Debt	650,000	1,350,000
Retirements of Long-Term Debt	(576,650)	(840,600)
Retirements of Rate Reduction Bonds	0	(82,139)
Other Financing Activities	(90)	(13,536)
Net Cash Flows Provided by/(Used in) Financing Activities	(282,459)	(105,797)
Net Increase/(Decrease) in Cash	(1,658)	12,193
Cash - Beginning of Year	43,364	45,748
Cash - End of Year	41,706	57,941
The Connecticut Light And Power Company [Member]
Operating Activities:
Net Income	200,560	219,188
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Depreciation	139,598	132,356
Deferred Income Tax Expense (Benefit)	(14,400)	89,084
Pension, SERP and PBOP Expense, Net of Contributions	8,050	16,182
Regulatory Over/(Under) Recoveries, Net	62,929	24,061
Amortization of Regulatory Assets/(Liabilities), Net	62,644	11,223
Proceeds from DOE Damages Claim	68,610	0
Other Noncash Income (Expense)	(11,290)	(8,759)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(87,922)	(44,523)
Taxes Receivable/(Accrued)	39,805	841
Accounts Payable	16,984	(101,949)
Other Current Assets and Liabilities	(2,575)	(29,106)
Net Cash Flows Provided by Operating Activities	482,993	308,598
Investing Activities:
Investments in Property, Plant and Equipment	(371,660)	(294,638)
Other Investing Activities	(4,539)	2,013
Net Cash Flows Used in Investing Activities	(376,199)	(292,625)
Financing Activities:
Cash Dividends on Common Stock	(128,400)	(114,000)
Cash Dividends on Preferred Stock	(4,169)	(4,169)
Increase/(Decrease) in Short-Term Debt	0	(89,000)
Issuance of Long-Term Debt	250,000	400,000
Increase/(Decrease) in Notes Payable to Affiliate	(181,900)	(62,200)
Retirements of Long-Term Debt	(150,000)	(125,000)
Capital Contributions from NU Parent	120,000
Other Financing Activities	(3,268)	(6,352)
Net Cash Flows Provided by/(Used in) Financing Activities	(97,737)	(721)
Net Increase/(Decrease) in Cash	9,057	15,252
Cash - Beginning of Year	7,237	1
Cash - End of Year	16,294	15,253
NSTAR Electric Company [Member]
Operating Activities:
Net Income	233,791	213,162
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Bad Debt Expense	15,250	19,012
Depreciation	140,996	136,323
Deferred Income Tax Expense (Benefit)	(39,399)	26,358
Pension, SERP and PBOP Expense, Net of Contributions	(11,046)	(55,195)
Regulatory Over/(Under) Recoveries, Net	155,357	(11,299)
Amortization of Regulatory Assets/(Liabilities), Net	(916)	173,289
Amortization of Rate Reduction Bonds	0	15,054
Proceeds from DOE Damages Claim	30,193
Other Noncash Income (Expense)	(56,851)	(48,291)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(47,770)	(80,575)
Increase Decrease in Fuel, Materials and Supplies	(20,837)	7,961
Taxes Receivable/(Accrued)	60,252	(6,345)
Accounts Payable	(40,594)	6,856
Other Current Assets and Liabilities	32,340	(19,547)
Accounts Payable Related Parties	66,758	(59,173)
Net Cash Flows Provided by Operating Activities	517,524	317,590
Investing Activities:
Investments in Property, Plant and Equipment	(309,248)	(330,635)
Decrease In Restricted Cash	0	37,899
Other Investing Activities	0	575
Net Cash Flows Used in Investing Activities	(309,248)	(292,161)
Financing Activities:
Cash Dividends on Common Stock	(253,000)	(56,000)
Cash Dividends on Preferred Stock	(1,470)	(1,633)
Increase/(Decrease) in Short-Term Debt	56,000	(120,000)
Issuance of Long-Term Debt	300,000	200,000
Retirements of Long-Term Debt	(301,650)	(1,650)
Retirements of Rate Reduction Bonds		(43,493)
Other Financing Activities	(5,137)	(878)
Net Cash Flows Provided by/(Used in) Financing Activities	(205,257)	(23,654)
Net Increase/(Decrease) in Cash	3,019	1,775
Cash - Beginning of Year	8,021	13,695
Cash - End of Year	11,040	15,470
Public Service Company Of New Hampshire [Member]
Operating Activities:
Net Income	84,955	84,543
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Depreciation	73,247	68,433
Deferred Income Tax Expense (Benefit)	67,827	57,066
Pension, SERP and PBOP Expense	4,541	20,427
Pension and PBOP Contributions	(1,637)	(112,964)
Regulatory Over/(Under) Recoveries, Net	16,813	(1,346)
Amortization of Regulatory Assets/(Liabilities), Net	(17,565)	(1,745)
Amortization of Rate Reduction Bonds	0	19,748
Proceeds from DOE Damages Claim	14,453
Other Noncash Income (Expense)	7,930	7,165
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(7,467)	8,047
Increase Decrease in Fuel, Materials and Supplies	(17,350)	(30,456)
Taxes Receivable/(Accrued)	(24,108)	5,103
Accounts Payable	(9,297)	29,148
Other Current Assets and Liabilities	13,470	7,220
Net Cash Flows Provided by Operating Activities	205,812	160,389
Investing Activities:
Investments in Property, Plant and Equipment	(170,127)	(155,676)
Decrease In Restricted Cash	(45)	22,039
Other Investing Activities	(103)	(53)
Net Cash Flows Used in Investing Activities	(170,275)	(133,690)
Financing Activities:
Cash Dividends on Common Stock	(49,500)	(51,000)
Increase/(Decrease) in Notes Payable to Affiliate	66,800	165,200
Retirements of Long-Term Debt	(50,000)	(108,950)
Retirements of Rate Reduction Bonds	0	(29,294)
Other Financing Activities	(217)	456
Net Cash Flows Provided by/(Used in) Financing Activities	(32,917)	(23,588)
Net Increase/(Decrease) in Cash	2,620	3,111
Cash - Beginning of Year	130	2,493
Cash - End of Year	2,750	5,604
Western Massachusetts Electric Company [Member]
Operating Activities:
Net Income	39,785	50,041
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Depreciation	31,144	27,707
Deferred Income Tax Expense (Benefit)	13,479	79,401
Regulatory Over/(Under) Recoveries, Net	33,630	11,685
Amortization of Regulatory Assets/(Liabilities), Net	(7,778)	(598)
Amortization of Rate Reduction Bonds	0	7,780
Proceeds from DOE Damages Claim	18,883
Other Noncash Income (Expense)	615	(544)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	36,075	(32,231)
Taxes Receivable/(Accrued)	(15,831)	16,412
Accounts Payable	(12,847)	20,260
Other Current Assets and Liabilities	(16,551)	(9,857)
Net Cash Flows Provided by Operating Activities	120,604	170,056
Investing Activities:
Investments in Property, Plant and Equipment	(82,546)	(127,352)
Proceeds from Sales of Marketable Securities	58,788	53,552
Purchases of Marketable Securities	(59,280)	(54,042)
Other Investing Activities	0	7,401
Net Cash Flows Used in Investing Activities	(83,038)	(120,441)
Financing Activities:
Cash Dividends on Common Stock	(49,000)	(30,000)
Increase/(Decrease) in Notes Payable to Affiliate	13,200	47,900
Retirements of Long-Term Debt		(55,000)
Retirements of Rate Reduction Bonds	0	(9,352)
Other Financing Activities	(29)	(7)
Net Cash Flows Provided by/(Used in) Financing Activities	(35,829)	(46,459)
Net Increase/(Decrease) in Cash	1,737	3,156
Cash - Beginning of Year	0	1
Cash - End of Year	$ 1,737	$ 3,157