Jointly Owned Facilities (Details) $ in Millions	Dec. 31, 2016 USD ($) MW
Oak Creek Expansion Units 1 and 2 \| We Power
Jointly Owned Electric Generating Facilities
Ownership (as a percentage)	83.34%
Share of rated capacity (MWs) (1) \| MW	1,056.8
Property, plant, and equipment	$ 2,430.8
Accumulated depreciation	(331.5)
Construction Work in Progress	$ 9.4
Weston 4 \| WPS
Jointly Owned Electric Generating Facilities
Ownership (as a percentage)	70.00%
Share of rated capacity (MWs) (1) \| MW	373.5
Property, plant, and equipment	$ 596.3
Accumulated depreciation	(170.3)
Construction Work in Progress	$ 0.2
Columbia Energy Center Units 1 and 2 \| WPS
Jointly Owned Electric Generating Facilities
Future Ownership Interest of Columbia	27.50%
Ownership (as a percentage)	31.80%
Share of rated capacity (MWs) (1) \| MW	334.4
Property, plant, and equipment	$ 417.9
Accumulated depreciation	(128.3)
Construction Work in Progress	$ 41.2
Edgewater Unit 4 \| WPS
Jointly Owned Electric Generating Facilities
Ownership (as a percentage)	31.80%
Share of rated capacity (MWs) (1) \| MW	98.0
Property, plant, and equipment	$ 45.8
Accumulated depreciation	(31.7)
Construction Work in Progress	$ 0.1

The period end amount owned by the reporting utility of a jointly owned utility plant in service.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 10.C)
-URI http://asc.fasb.org/extlink&oid=6500719&loc=d3e659983-123033

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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 period end amount of construction work in progress at a jointly owned electricity generation plant.

+ References

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- Definition

The period end amount of accumulated depreciation in a jointly owned electricity generation plant.

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- Definition

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

+ References

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The future proportionate share of interest (percent) in Columbia as capital expenditures increase by Columbia and not WPS, through June 1, 2020

+ References

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- Definition

The entity's proportionate share of the rated capacity of a jointly owned utility plant.

+ References

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