SHORT-TERM DEBT (Tables)

12 Months Ended

Dec. 31, 2020

Debt Disclosure [Abstract]

Schedule of Borrowings Outstanding

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)	2020		2019		2020		2019		2020		2019
Eversource Parent Commercial Paper Program	$	1,054.3	$	1,224.9	$	945.7	$	225.1	0.25	%	1.98	%
NSTAR Electric Commercial Paper Program	195.0		10.5		455.0		639.5		0.16	%	1.63	%

Details of long-term debt outstanding are as follows:

CL&P (Millions of Dollars)	As of December 31,
	2020		2019
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
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	500.0		500.0
4.000% 2018 Series A due 2048	800.0		800.0
0.750% 2020 Series A due 2025	400.0		—
Total First Mortgage Bonds	3,794.8		3,394.8
Pollution Control Revenue Bonds:
4.375% Fixed Rate Tax Exempt due 2028	120.5		120.5
Less Amounts due Within One Year	—		—
Unamortized Premiums and Discounts, Net	25.9		27.8
Unamortized Debt Issuance Costs	(26.4)		(25.0)
CL&P Long-Term Debt	$	3,914.8	$	3,518.1

NSTAR Electric (Millions of Dollars)	As of December 31,
	2020		2019
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
3.250% due 2029	400.0		400.0
3.950% due 2030	400.0		—
Total Debentures	3,200.0		2,800.0
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
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	470.0		565.0
Less Amounts due Within One Year	(250.0)		(95.0)
Unamortized Premiums and Discounts, Net	(6.8)		(4.1)
Unamortized Debt Issuance Costs	(20.0)		(18.8)
NSTAR Electric Long-Term Debt	$	3,393.2	$	3,247.1

PSNH (Millions of Dollars)	As of December 31,
	2020		2019
First Mortgage Bonds:
5.600% Series M due 2035	$	50.0	$	50.0
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
3.600% Series T due 2049	300.0		300.0
2.400% Series U due 2050	150.0		—
Total First Mortgage Bonds	$	1,107.0	$	957.0
Less Amounts due Within One Year	(282.0)		—
Unamortized Premiums and Discounts, Net	(1.5)		(0.7)
Unamortized Debt Issuance Costs	(6.4)		(4.7)
PSNH Long-Term Debt	$	817.1	$	951.6

OTHER (Millions of Dollars)	As of December 31,
	2020		2019
Yankee Gas - First Mortgage Bonds: 2.230% - 8.480% due 2022 - 2050	$	640.0	$	620.0
NSTAR Gas - First Mortgage Bonds: 2.330% - 7.110% due 2025 - 2050	500.0		460.0
Aquarion - Senior Note 4.000% due 2024	360.0		360.0
Aquarion - Unsecured Notes 0% - 6.430% due 2021 - 2049	335.2		335.3
Aquarion - Secured Debt 4.450% - 9.290% due 2022 - 2035	35.9		68.8
Eversource Parent - Senior Notes 0.800% - 4.250% due 2021 - 2050	5,550.0		4,000.0
Pre-1983 Spent Nuclear Fuel Obligation (CYAPC)	11.7		11.6
Fair Value Adjustment (1)	74.7		109.1
Less Fair Value Adjustment - Current Portion (1)	(31.0)		(31.3)
Less Amounts due in One Year	(490.2)		(201.1)
Commercial Paper Classified as Long-Term Debt	—		346.3
Unamortized Premiums and Discounts, Net	46.5		(4.1)
Unamortized Debt Issuance Costs	(32.0)		(20.6)
Total Other Long-Term Debt	$	7,000.8	$	6,054.0
Total Eversource Long-Term Debt	$	15,125.9	$	13,770.8

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