The minimum common equity ratio required to avoid dividend payment restirctions to the parent company.

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Aggregate dividends paid during the period for each share of common stock outstanding.

+ References

+ Details

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- Definition

Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

+ References

+ Details

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- Definition

Amount of paid and unpaid paid-in-kind dividends (PIK) declared for classes of stock, for example, but not limited to, common and preferred.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6957935&loc=d3e64057-112817

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- Definition

The distributions of earnings to an entity that is affiliated with the reporting entity by means of direct or indirect ownership.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

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- Details

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- Details

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- Details

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Common Equity (Details) $ / shares in Units, $ in Thousands		3 Months Ended								12 Months Ended
Common Equity (Details) $ / shares in Units, $ in Thousands	Dec. 01, 2016 USD ($)	Dec. 31, 2017 $ / shares	Sep. 30, 2017 $ / shares	Jun. 30, 2017 $ / shares	Mar. 31, 2017 $ / shares	Dec. 31, 2016 $ / shares	Sep. 30, 2016 $ / shares	Jun. 30, 2016 $ / shares	Mar. 31, 2016 $ / shares	Dec. 31, 2017 USD ($) $ / shares	Dec. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares
Class of Stock [Line Items]
Common stock dividends declared										$ 43,682	$ 41,775	$ 40,043
Common stock dividends declared (in dollars per share) \| $ / shares		$ 0.323	$ 0.323	$ 0.308	$ 0.308	$ 0.308	$ 0.308	$ 0.295	$ 0.295	$ 1.26	$ 1.21	$ 1.16
MGE Energy [Member]
Class of Stock [Line Items]
Dividend in kind to parent	$ (15,800)
MGE [Member]
Class of Stock [Line Items]
Cash dividends paid to parent by MGE										$ 45,000	$ 50,000	$ 30,000
Dividend in kind to parent	$ 15,800									$ 0	$ 15,822	$ 0
MGE [Member] \| Minimum [Member]
Class of Stock [Line Items]
Dividend restrictions, common equity ratio										0.55