SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	12 Months Ended
Dec. 31, 2014
Cash and Cash Equivalents
Maximum maturity of short-term investments to classify as cash equivalents	3 months
Integrys Energy Group, Inc.
Cash and Cash Equivalents
Maximum maturity of short-term investments to classify as cash equivalents	3 months

Maximum term of original maturity to classify an instrument as a cash equivalent.

No definition available.

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