MARKETABLE SECURITIES (Tables)

12 Months Ended

Dec. 31, 2015

Notes To Consolidated Financial Statements [Abstract]

Schedule Of Available For Sale Securities Reconciliation [Table TextBlock]

		As of December 31,
		2015								2014
				Pre-Tax		Pre-Tax						Pre-Tax		Pre-Tax
		Amortized		Unrealized		Unrealized				Amortized		Unrealized		Unrealized
(Millions of Dollars)		Cost		Gains		Losses		Fair Value		Cost		Gains		Losses		Fair Value
Eversource
	Debt Securities (1) (2)	$	256.5	$	4.5	$	(0.6)	$	260.4	$	313.0	$	7.5	$	(0.3)	$	320.2
	Equity Securities (1)		215.3		59.2		(3.4)		271.1		160.6		73.3		-		233.9
WMECO
	Debt Securities (2)		-		-		-		-		58.2		-		(0.1)		58.1

Investments Classified by Contractual Maturity Date [Table Text Block]

Eversource	Amortized		Fair
(Millions of Dollars)	Cost		Value
Less than one year (1)	$	33.3	$	33.2
One to five years		50.2		50.7
Six to ten years		56.6		57.2
Greater than ten years		116.4		119.3
Total Debt Securities	$	256.5	$	260.4

Fair Value Heirarchy [Table Text Block]

Eversource		As of December 31,
(Millions of Dollars)		2015		2014
Level 1:
	Mutual Funds and Equities	$	285.3	$	319.0
	Money Market Funds		26.9		24.9
Total Level 1		$	312.2	$	343.9
Level 2:
	U.S. Government Issued Debt Securities (Agency and Treasury)	$	46.6	$	51.3
	Corporate Debt Securities		43.9		49.1
	Asset-Backed Debt Securities		20.0		54.1
	Municipal Bonds		111.4		116.3
	Other Fixed Income Securities		11.6		24.5
Total Level 2		$	233.5	$	295.3
Total Marketable Securities		$	545.7	$	639.2