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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Number of shares of equity interests issued or issuable to acquire entity.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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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, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Notes To Consolidated Financial Statements [Abstract]
Net Income Attributable to Controlling Interests		$ 221,500	$ 234,600	$ 127,400	$ 236,000	$ 177,400	$ 209,500	$ 171,000	$ 228,100	$ 819,546	$ 786,007	$ 525,945
Basic										316,136,748	315,311,387	277,209,819
Weighted Average Number Diluted Shares Outstanding Adjustment										1,280,666	899,773	783,812
Diluted										317,417,414	316,211,160	277,993,631
Earnings Per Share Basic And Diluted		$ 0.69us-gaap_EarningsPerShareBasicAndDiluted	$ 0.74us-gaap_EarningsPerShareBasicAndDiluted	$ 0.40us-gaap_EarningsPerShareBasicAndDiluted	$ 0.75us-gaap_EarningsPerShareBasicAndDiluted	$ 0.56us-gaap_EarningsPerShareBasicAndDiluted	$ 0.66us-gaap_EarningsPerShareBasicAndDiluted	$ 0.54us-gaap_EarningsPerShareBasicAndDiluted	$ 0.72us-gaap_EarningsPerShareBasicAndDiluted
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount										3,643	1,575	4,266
Basic Earnings Per Common Share										$ 2.59us-gaap_EarningsPerShareBasic	$ 2.49us-gaap_EarningsPerShareBasic	$ 1.90us-gaap_EarningsPerShareBasic
Diluted Earnings Per Common Share										$ 2.58us-gaap_EarningsPerShareDiluted	$ 2.49us-gaap_EarningsPerShareDiluted	$ 1.89us-gaap_EarningsPerShareDiluted
Common Stock Issuance Merger With Nstar [Abstract]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	136,049,000