PROPERTY, PLANT AND ACCUMULATED DEPRECIATION (Tables)

6 Months Ended

Jun. 30, 2016

Notes To Consolidated Financial Statements [Abstract]

Schedule of Public Utility Property, Plant, and Equipment [Text Block]

		As of June 30, 2016		As of December 31, 2015
(Millions of Dollars)		Eversource		Eversource
Distribution - Electric		$	13,425.4	$	13,054.8
Distribution - Natural Gas			2,819.9		2,727.2
Transmission - Electric			7,896.3		7,691.9
Generation			1,218.3		1,194.1
Electric and Natural Gas Utility			25,359.9		24,668.0
Other (1)			583.5		558.6
Property, Plant and Equipment, Gross			25,943.4		25,226.6
Less: Accumulated Depreciation
	Electric and Natural Gas Utility		(6,342.9)		(6,141.1)
	Other		(274.5)		(255.6)
Total Accumulated Depreciation			(6,617.4)		(6,396.7)
Property, Plant and Equipment, Net			19,326.0		18,829.9
Construction Work in Progress			1,122.5		1,062.5
Total Property, Plant and Equipment, Net		$	20,448.5	$	19,892.4

	As of June 30, 2016								As of December 31, 2015
			NSTAR								NSTAR
(Millions of Dollars)	CL&P		Electric		PSNH		WMECO		CL&P		Electric		PSNH		WMECO
Distribution	$	5,471.5	$	5,279.1	$	1,883.8	$	831.0	$	5,377.2	$	5,100.5	$	1,804.8	$	812.3
Transmission		3,691.2		2,205.3		972.0		977.9		3,618.0		2,131.3		928.2		964.9
Generation		-		-		1,182.4		35.9		-		-		1,158.1		36.0
Property, Plant and Equipment, Gross		9,162.7		7,484.4		4,038.2		1,844.8		8,995.2		7,231.8		3,891.1		1,813.2
Less: Accumulated Depreciation		(2,089.2)		(1,962.7)		(1,217.3)		(323.0)		(2,041.9)		(1,886.8)		(1,171.0)		(307.0)
Property, Plant and Equipment, Net		7,073.5		5,521.7		2,820.9		1,521.8		6,953.3		5,345.0		2,720.1		1,506.2
Construction Work in Progress		263.1		267.0		104.4		94.5		203.5		310.5		135.3		69.1
Total Property, Plant and Equipment, Net	$	7,336.6	$	5,788.7	$	2,925.3	$	1,616.3	$	7,156.8	$	5,655.5	$	2,855.4	$	1,575.3