DISPOSITIONS - DISCONTINUED OPERATIONS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Discontinued operations recorded in income statements
Discontinued operations, net of tax	$ (0.1)	$ (0.8)	$ (0.2)	$ 5.3
Holding Company and Other
Discontinued operations recorded in income statements
Discontinued operations, net of tax		(0.1)		5.9
Integrys Energy Services | Combined Locks Energy Center
Assets classified as held for sale on balance sheets
Total assets	0.7		0.7		0.7
Discontinued operations recorded in income statements
Discontinued operations, net of tax	(0.1)	(0.7)	(0.2)	(0.8)
Integrys Energy Services | WPS Empire State, Inc | WPS Beaver Falls Generation, LLC and WPS Syracuse Generation, LLC
Discontinued operations recorded in income statements
Discontinued operations, net of tax				$ 0.2