DOCUMENT AND ENTITY INFORMATION	9 Months Ended
	Sep. 30, 2018 shares
Document Entity Information [Abstract]
Entity registrant name	WISCONSIN PUBLIC SERVICE CORP
Entity central index key	0000107833
Document type	10-Q
Document period end date	Sep. 30, 2018
Amendment flag	false
Current fiscal year end date	--12-31
Entity filer category	Non-accelerated Filer
Entity common stock, shares outstanding	23,896,962
Document fiscal year focus	2018
Document fiscal period focus	Q3
Emerging growth company	false
Small business	false