The aggregate purchase price for the Forward Wind site.

No definition available.

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- Definition

The total operating turbines on the Forward Wind windfarm.

+ References

No definition available.

+ Details

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- Definition

MGE's purchase power energy output with Forward Wind.

+ References

No definition available.

+ Details

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- Definition

The total operating capacity (in megawatts) of the Forward Wind utility plant.

+ References

No definition available.

+ Details

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- Definition

Amount of asset retirement obligations incurred during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

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- Definition

Amount of assets held-for-sale that are not part of a disposal group, expected to be sold within a year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 15
-Paragraph 4
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=77912953&loc=d3e400-110220

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- Definition

Future cash outflow to pay for purchases of fixed assets that have occurred.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
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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.

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- Definition

The total period end amount of plant in service and construction in progress net of accumulated depreciation for the utility's share of jointly owned electricity generation plant.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 360
-Section S99
-Paragraph 1
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- Definition

The proportionate share of interest (percent) in a jointly owned utility plant.

+ References

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Joint Plant Ownership (Details) $ in Thousands	3 Months Ended	6 Months Ended		12 Months Ended
Joint Plant Ownership (Details) $ in Thousands	Jun. 30, 2018 USD ($) Turbines MW	Jun. 30, 2018 USD ($) Turbines MW	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2018	Jan. 01, 2018
Jointly Owned Utility Plant Interests [Line Items]
Assets held for sale	$ 1,392	$ 1,392		$ 8,817
Accrued capital expenditures		6,467	$ 8,450
Forward Wind Purchase Power Energy Output				12.80%	12.80%
MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Assets held for sale	1,392	1,392		$ 8,817
Accrued capital expenditures		6,467	$ 8,450
Columbia Units [Member] \| MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, ownership interest				20.40%		19.40%
Assets held for sale	1,400	1,400		$ 8,800
Accrued capital expenditures	$ 100	$ 1,400		$ 8,800
Forward Wind Units [Member] \| MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, ownership interest	12.80%	12.80%
Jointly owned utility plant, plant capacity (in MW) \| MW	129	129
Forward Wind Turbines \| Turbines	86	86
Forward Wind Proportionate Purchase Price	$ 23,000	$ 23,000
Forward Wind Purchase Power Energy Output				12.80%	12.80%
Forward Wind Asset Retirement Obligation	1,600	1,600
Forward Wind Units [Member] \| Joint Owners [Member]
Jointly Owned Utility Plant Interests [Line Items]
Forward Wind Aggregate Purchase Price	$ 174,000	$ 174,000