INCOME TAXES - Components of Income Before Income Taxes (Details) - MGE Niagara - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018
Income Tax Contingency [Line Items]
Domestic	$ 3,909	$ 138,453
Foreign	(5,256)	(6,370)
Total	$ (1,347)	$ 132,083

The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

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Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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