EARNINGS PER SHARE (Details) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended								12 Months Ended
	Apr. 09, 2012	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Notes To Consolidated Financial Statements [Abstract]
Net Income Attributable to Controlling Interests		$ 177,400	$ 209,500	$ 171,000	$ 228,100	$ 174,700	$ 207,600	$ 44,300	$ 99,300	$ 786,007	$ 525,945	$ 394,693
Basic										315,311,387	277,209,819	177,410,167
Weighted Average Number Diluted Shares Outstanding Adjustment										899,773	783,812	394,401
Diluted										316,211,160	277,993,631	177,804,568
Earnings Per Share Basic And Diluted		$ 0.56	$ 0.66	$ 0.54	$ 0.72	$ 0.55	$ 0.66	$ 0.15	$ 0.56
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount										1,575	4,266	4,314
Basic Earnings Per Common Share										$ 2.49	$ 1.90	$ 2.22
Diluted Earnings Per Common Share										$ 2.49	$ 1.89	$ 2.22
Common Stock Issuance Merger With Nstar [Abstract]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	136,049,000