ACQUISITIONS - Pro Forma Information, Revenues and Earnings of MGE (Details) (Missouri Gas Energy (MGE), USD $) In Millions, except Per Share data, unless otherwise specified	1 Months Ended	12 Months Ended
Sep. 30, 2013	Sep. 30, 2014
Missouri Gas Energy (MGE)
Pro Forma Information of Acquiree since Acquisition Date
Total net revenues	$ 22.0	$ 554.2
Net Income	$ 1.8	$ 39.5
Earnings per share:
Basic (in dollars per share)	$ 0.07	$ 1.10
Diluted (in dollars per share)	$ 0.07	$ 1.10

Business Combination, Pro Forma Information, Earnings Per Share of Acquiree since Acquisition Date, Basic, Actual

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- Definition

Business Combination, Pro Forma Information, Earnings Per Share of Acquiree since Acquisition Date, Diluted, Actual

+ References

No definition available.

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- Definition

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

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- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

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