Supplemental Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2012

Notes To Consolidated Financial Statements [Abstract]

Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]

P.		Supplemental Cash Flow Information
NU			As of and For the Years Ended December 31,
(Millions of Dollars)			2012		2011		2010
Cash Paid/(Received) During the Year for:
	Interest, Net of Amounts Capitalized		$	356.5	$	256.3	$	258.3
	Income Taxes			(12.8)		(76.6)		84.5
Non-Cash Investing Activities:
	Plant Additions Included in Accounts Payable (As of)			160.6		168.5		127.9

		As of and For the Years Ended December 31,
		2012								2011								2010
				NSTAR								NSTAR								NSTAR
(Millions of Dollars)		CL&P		Electric (1)		PSNH		WMECO		CL&P		Electric (1)		PSNH		WMECO		CL&P		Electric (1)		PSNH		WMECO
Cash Paid/(Received) During
	the Year for:
	Interest, Net of Amounts
	Capitalized	$	129.4	$	94.6	$	49.8	$	25.8	$	136.6	$	96.1	$	49.3	$	22.1	$	142.2	$	95.8	$	51.4	$	20.2
	Income Taxes		(42.0)		88.1		14.7		(8.4)		(27.5)		(62.2)		(29.0)		(4.9)		71.5		147.6		1.6		5.0
Non-Cash Investing Activities:
	Plant Additions Included in
	Accounts Payable (As of)		42.8		50.0		16.8		30.0		32.7		34.3		51.1		61.3		46.2		16.7		35.8		21.2