SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 8) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Minimum
Income Taxes
Threshold ownership percentage used to determine subsidiary inclusion in consolidated income tax return	80.00%
WPS
Capitalized Interest and AFUDC
Percentage of retail jurisdictional construction work in progress expenditures subject to AFUDC calculation	50.00%
Average AFUDC retail rate (as a percent)	7.71%
Average AFUDC wholesale rate (as a percent)	4.16%
Allowance for equity funds used during construction	$ 0.6	$ 0.7	$ 5.1
Allowance for borrowed funds used during construction	$ 0.2	$ 0.3	$ 2.0

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Represents the ownership threshold used to determine whether subsidiaries are included in the entity's consolidated federal income tax return.

+ References

No definition available.

+ Details

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- Definition

Represents the percentage of retail jurisdictional construction work in progress expenditures subject to the AFUDC calculation.

+ References

No definition available.

+ Details

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- Definition

Represents the average allowance for funds used during construction average retail rate.

+ References

No definition available.

+ Details

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- Definition

Represents the average allowance for funds used during construction average wholesale rate.

+ References

No definition available.

+ Details

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- Details

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- Definition

The component of the allowance for funds used during construction during the period comprised of interest on borrowed funds used in financing the construction of regulated assets, which may be reflected as a reduction of interest expense.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 71

-Paragraph 15

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 835

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6501569&loc=d3e55921-110430

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 835

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6501662&loc=d3e56162-110433

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- Definition

Discloses the amount of any allowance for earnings on shareholders' investment capitalized for rate making purposes but not for the financial statements.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 92

-Paragraph 8, 9, 12

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 340

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44278-110382

+ Details

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