LONG-TERM DEBT (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Schedule of Debt

The amount of borrowings outstanding and available under the commercial paper programs were as follows:

	Borrowings Outstanding  as of December 31,				Available Borrowing Capacity as of December 31,				Weighted-Average Interest Rate as of December 31,
(Millions of Dollars)	2018		2017		2018		2017		2018		2017
Eversource Parent Commercial Paper Program	$	631.5	$	979.3	$	818.5	$	470.7	2.77	%	1.86	%
NSTAR Electric Commercial Paper Program	278.5		234.0		371.5		416.0		2.50	%	1.55	%

Details of long-term debt outstanding are as follows:

CL&P (Millions of Dollars)	As of December 31,
	2018			2017
First Mortgage Bonds:
7.875% 1994 Series D due 2024	$	139.8		$	139.8
5.750% 2004 Series B due 2034	130.0			130.0
5.625% 2005 Series B due 2035	100.0			100.0
6.350% 2006 Series A due 2036	250.0			250.0
5.750% 2007 Series B due 2037	150.0			150.0
6.375% 2007 Series D due 2037	100.0			100.0
5.650% 2008 Series A due 2018	—			300.0
5.500% 2009 Series A due 2019	250.0			250.0
2.500% 2013 Series A due 2023	400.0			400.0
4.300% 2014 Series A due 2044	475.0			475.0
4.150% 2015 Series A due 2045	350.0			350.0
3.200% 2017 Series A due 2027	300.0			300.0
4.000% 2018 Series A due 2048	500.0			—
Total First Mortgage Bonds	3,144.8			2,944.8
Pollution Control Revenue Bonds:
4.375% Fixed Rate Tax Exempt due 2028	120.5			120.5
Less Amounts due Within One Year	(250.0		)	(300.0		)
Unamortized Premiums and Discounts, Net	10.2			11.5
Unamortized Debt Issuance Costs	(21.5		)	(17.7		)
CL&P Long-Term Debt	$	3,004.0		$	2,759.1

NSTAR Electric (Millions of Dollars)	As of December 31,
	2018			2017
Debentures:
5.750% due 2036	$	200.0		$	200.0
5.500% due 2040	300.0			300.0
2.375% due 2022	400.0			400.0
4.400% due 2044	300.0			300.0
3.250% due 2025	250.0			250.0
2.700% due 2026	250.0			250.0
3.200% due 2027	700.0			700.0
Total Debentures	2,400.0			2,400.0
Notes:
5.900% Senior Notes Series B due 2034	50.0			50.0
6.700% Senior Notes Series D due 2037	40.0			40.0
5.100% Senior Notes Series E due 2020	95.0			95.0
3.500% Senior Notes Series F due 2021	250.0			250.0
3.880% Senior Notes Series G due 2023	80.0			80.0
2.750% Senior Notes Series H due 2026	50.0			50.0
Total Notes	565.0			565.0
Less Amounts due Within One Year	—			—
Unamortized Premiums and Discounts, Net	(2.5		)	(1.8		)
Unamortized Debt Issuance Costs	(17.7		)	(19.4		)
NSTAR Electric Long-Term Debt	$	2,944.8		$	2,943.8

PSNH (Millions of Dollars)	As of December 31,
	2018			2017
First Mortgage Bonds:
5.600% Series M due 2035	$	50.0		$	50.0
6.000% Series O due 2018	—			110.0
4.500% Series P due 2019	150.0			150.0
4.050% Series Q due 2021	122.0			122.0
3.200% Series R due 2021	160.0			160.0
3.500% Series S due 2023	325.0			325.0
Total First Mortgage Bonds	807.0			917.0
Pollution Control Revenue Bonds:
Adjustable Rate Tax Exempt Series A due 2021	—			89.3
Less Amounts due Within One Year	(150.0		)	(110.0		)
Unamortized Premiums and Discounts, Net	—			0.2
Unamortized Debt Issuance Costs	(1.8		)	(4.1		)
PSNH Long-Term Debt	$	655.2		$	892.4

OTHER (Millions of Dollars)	As of December 31,
	2018			2017
Yankee Gas - First Mortgage Bonds: 3.020% - 8.480% due 2019 - 2048	$	470.0		$	520.0
NSTAR Gas - First Mortgage Bonds: 4.09% - 9.950% due 2020 - 2048	385.0			285.0
Eversource Parent and Other - Notes and Debentures:
4.500% Debentures due 2019	350.0			350.0
2.500% - 4.250% Senior Notes due 2021 - 2029	4,360.0			3,260.0
Unsecured Notes 3.570% - 6.430% due 2021 - 2037	289.5			290.9
Secured Debt 4.100% - 9.640% due 2021 - 2035	70.7			70.4
Pre-1983 Spent Nuclear Fuel Obligation (CYAPC)	39.5			181.4
Fair Value Adjustment (1)	144.7			172.6
Less Fair Value Adjustment - Current Portion (1)	(36.2		)	(35.4		)
Less Amounts due in One Year	(401.1		)	(104.2		)
Commercial Paper Classified as Long-Term Debt	—			201.2
Unamortized Premiums and Discounts, Net	(4.2		)	1.5
Unamortized Debt Issuance Costs	(23.2		)	(12.8		)
Total Other Long-Term Debt	$	5,644.7		$	5,180.6
Total Eversource Long-Term Debt	$	12,248.7		$	11,775.9

⁽¹⁾ The fair value adjustment amount is the purchase price adjustments, net of amortization, required to record the NSTAR long-term debt at fair value on the date of the 2012 merger and to record the Aquarion long-term debt at fair value on the date of the 2017 acquisition.

Schedule of Long-term Debt Instruments

The following table summarizes long-term debt issuances and repayments:

(Millions of Dollars)	Issue Date	Issuances/(Repayments)			Maturity Date	Use of Proceeds for Issuances/ Repayment Information
CL&P:
4.00% 2018 Series A First Mortgage Bonds	March 2018	$	500.0		April 2048	Repaid long-term debt that matured in 2018 and repaid short-term borrowings
5.65% 2008 Series A First Mortgage Bonds	May 2008	(300.0		)	May 2018	Repaid at maturity on May 1, 2018
PSNH:
6.00% 2008 Series O First Mortgage Bonds	May 2008	(110.0		)	May 2018	Repaid at maturity on May 1, 2018
2001 Series A Pollution Control Revenue Bonds	December 2001	(89.3		)	May 2021	Redeemed on November 28, 2018 at a redemption price of $89.3 million
Other:
Eversource Parent 2.50% Series I Senior Notes (1)	January 2018	200.0			March 2021	Repaid short-term borrowings
Eversource Parent 3.30% Series M Senior Notes	January 2018	450.0			January 2028	Repaid long-term debt that matured in 2018
Eversource Parent 3.80% Series N Senior Notes	December 2018	400.0			December 2023	Repaid short-term borrowings
Eversource Parent 4.25% Series O Senior Notes	December 2018	500.0			April 2029	Repaid short-term borrowings
Eversource Parent 1.60% Series G Senior Notes	January 2015	(150.0		)	January 2018	Repaid at maturity on January 15, 2018
Eversource Parent 1.45% Series E Senior Notes	May 2013	(300.0		)	May 2018	Repaid at maturity on May 1, 2018
Yankee Gas 4.13% Series O First Mortgage Bonds	September 2018	50.0			October 2048	Repaid long-term debt that matured in 2018
Yankee Gas 6.90% Series J First Mortgage Bonds	October 2008	(100.0		)	October 2018	Repaid at maturity on October 1, 2018
NSTAR Gas 4.09% Series P First Mortgage Bonds	September 2018	100.0			October 2048	Repaid short-term borrowings

⁽¹⁾ These notes are part of the same series issued by Eversource parent in March 2016. The aggregate outstanding principal amount of these notes is now $450 million.

Schedule of Maturities of Long-term Debt

Long-term debt maturities on debt outstanding for the years 2019 through 2023 and thereafter are shown below. These amounts exclude the CYAPC pre-1983 spent nuclear fuel obligation, net unamortized premiums, discounts and debt issuance costs, and other fair value adjustments as of December 31, 2018:

(Millions of Dollars)	Eversource		CL&P		NSTAR Electric		PSNH
2019	$	801.1	$	250.0	$	—	$	150.0
2020	296.1		—		95.0		—
2021	1,033.5		—		250.0		282.0
2022	1,188.9		—		400.0		—
2023	1,665.2		400.0		80.0		325.0
Thereafter	7,977.7		2,615.3		2,140.0		50.0
Total	$	12,962.5	$	3,265.3	$	2,965.0	$	807.0