GOODWILL (Details) (USD $)	0 Months Ended	12 Months Ended
	Apr. 09, 2012	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Line item]
Goodwill Acquired During Period	$ 3,232,000,000	$ 3,200,000,000
Goodwill			3,519,401,000	3,519,401,000
Yankee Gas Services Company [Member]
Goodwill [Line item]
Goodwill			300,000,000	300,000,000
Electric Distribution Member
Goodwill [Line item]
Goodwill			2,500,000,000	2,500,000,000
Transmission [Member]
Goodwill [Line item]
Goodwill			600,000,000	600,000,000
Natural Gas Distribution [Member]
Goodwill [Line item]
Goodwill			$ 400,000,000	$ 400,000,000