SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES BASIS OF PRESENTATION (Details)	Dec. 31, 2014
Accounting Policies [Abstract]
Number of wholly owned subsidiaries	1wps_NumberOfWhollyOwnedSubsidiaries

Number of subsidiaries wholly owned by the entity.

No definition available.

Name:	wps_NumberOfWhollyOwnedSubsidiaries
Namespace Prefix:	wps_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant