CONSOLIDATED STATEMENT OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash Flows From Operating Activities
Net income	$ 103,701	$ 99,710	$ 54,857
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	183,785	170,237	115,734
Deferred income taxes	68,121	83,273	57,042
Allowance for funds used during construction (AFUDC) - equity	(7,480)	(10,539)	(7,174)
Stock-based compensation expense (Note A)	4,907	5,286	4,080
Pension expense	39,906	39,028	28,811
Undistributed (earnings) losses in equity investments	(15,440)	(11,702)	(1,440)
Excess generation service charge	4,894	(5,047)	(28,217)
Deferred Transmission (income) expense	(33,007)	(15,408)	36,009
Other non-cash items, net	4,962	(48,632)	(14,643)
Changes in:
Accounts receivable, net	(51,301)	34,654	(62,370)
Unbilled revenues	(11,999)	9,693	(9,830)
Natural gas in storage	26,748	(3,436)	23,553
Cash distribution received from GenConn	19,672	7,977	0
Accounts payable	(20,221)	4,446	25,209
Interest accrued	900	(1,341)	8,954
Taxes accrued/refundable, net	60,614	(41,366)	(29,598)
Accrued liabilities	16,271	(2,528)	7,962
Accrued pension	(59,317)	(77,005)	(8,862)
Other assets	6,811	2,750	2,605
Other liabilities	(8,586)	(17,188)	12,651
Total Adjustments	230,240	123,152	160,476
Net Cash provided by Operating Activities	333,941	222,862	215,333
Cash Flows from Investing Activities
Acquisition of Gas Companies, net of cash acquired	0	11,211	(856,952)
Related party note receivable	0	(1,050)	(9,750)
Plant expenditures including AFUDC debt	(288,633)	(328,079)	(203,530)
Investment in GenConn	0	(2,000)	(6,000)
Cash distributions from GenConn	1,872	0	0
Changes in restricted cash	3,717	(4,123)	1,297
Deposits in New England East West Solution (NEEWS) (Note C)	(24,059)	(2,393)	(7,231)
Other	844	401	(114)
Net Cash (used in) Investing Activities	(306,259)	(326,033)	(1,082,280)
Cash Flows from Financing Activities
Issuance of common stock	1,943	200	502,220
Issuances of long-term debt	203,500	51,050	556,109
Payments on long-term debt	(109,955)	(146,573)	(59,826)
Line of credit borrowings (repayments), net	(48,000)	228,000	2,100
Payment of common stock dividend	(87,490)	(87,274)	(51,836)
Other	(822)	(1,514)	(6,808)
Net Cash provided by (used in) Financing Activities	(40,824)	43,889	941,959
Unrestricted Cash and Temporary Cash Investments:
Net change for the period	(13,142)	(59,282)	75,012
Balance at beginning of period	30,999	90,281	15,269
Balance at end of period	17,857	30,999	90,281
Cash paid during the period for:
Interest (net of amount capitalized)	81,658	83,365	33,395
Income taxes	4,750	11,475	24,600
Non-cash investing activity:
Plant expenditures included in ending accounts payable	47,475	45,046	54,492
Related party note receivable (Note H)	0	62,833	55,540
Equity investment in Related Party (Note H)	0	(62,833)	(55,540)
Plant expenditures funded by deposits in NEEWS	(6,346)	0	0
Deposits in New England East West Solution (NEEWS)	$ 6,346	$ 0	$ 0