SEGMENTS OF BUSINESS (Tables)

9 Months Ended

Sep. 30, 2013

Segment Reporting [Abstract]

Schedule of information related to reportable segments

The table below presents information related to our reportable segments:

	Regulated Utilities
(Millions)	Electric Utility			Natural Gas Utility			Total Utility			Other		Reconciling Eliminations			WPS Consolidated
Three Months Ended September 30, 2013
External revenues	$	331.7		$	40.2		$	371.9		$	—	$	—		$	371.9
Intersegment revenues	—			4.1			4.1			0.5		(4.6		)	—
Depreciation and amortization expense	23.6			3.9			27.5			0.2		(0.1		)	27.6
Miscellaneous income	2.8			—			2.8			3.2		—			6.0
Interest expense	7.9			2.1			10.0			0.7		—			10.7
Provision (benefit) for income taxes	23.8			(2.0		)	21.8			1.0		—			22.8
Preferred stock dividend requirements	(0.6		)	(0.1		)	(0.7		)	—		—			(0.7		)
Net income (loss) attributed to common shareholder	38.3			(3.0		)	35.3			1.7		—			37.0
	Regulated Utilities
(Millions)	Electric Utility			Natural Gas Utility			Total Utility			Other		Reconciling Eliminations			WPS Consolidated
Three Months Ended September 30, 2012
External revenues	$	343.1		$	35.0		$	378.1		$	—	$	—		$	378.1
Intersegment revenues	—			4.4			4.4			0.3		(4.7		)	—
Depreciation and amortization expense	20.3			3.8			24.1			0.1		(0.1		)	24.1
Miscellaneous income	0.8			0.1			0.9			2.9		—			3.8
Interest expense	8.0			2.0			10.0			0.5		—			10.5
Provision (benefit) for income taxes	17.3			(3.8		)	13.5			0.9		—			14.4
Preferred stock dividend requirements	(0.6		)	(0.1		)	(0.7		)	—		—			(0.7		)
Net income (loss) attributed to common shareholder	43.9			(2.7		)	41.2			1.3		—			42.5
	Regulated Utilities
(Millions)	Electric Utility			Natural Gas Utility			Total Utility			Other		Reconciling Eliminations			WPS Consolidated
Nine Months Ended September 30, 2013
External revenues	$	946.0		$	227.1		$	1,173.1		$	—	$	—		$	1,173.1
Intersegment revenues	—			8.3			8.3			1.1		(9.4		)	—
Depreciation and amortization expense	66.9			11.8			78.7			0.5		(0.4		)	78.8
Miscellaneous income	6.5			0.1			6.6			10.3		—			16.9
Interest expense	23.8			6.4			30.2			1.7		—			31.9
Provision for income taxes	52.9			8.9			61.8			2.9		—			64.7
Preferred stock dividend requirements	(1.9		)	(0.4		)	(2.3		)	—		—			(2.3		)
Net income attributed to common shareholder	87.1			14.4			101.5			6.0		—			107.5
	Regulated Utilities
(Millions)	Electric Utility			Natural Gas Utility			Total Utility			Other		Reconciling Eliminations			WPS Consolidated
Nine Months Ended September 30, 2012
External revenues	$	922.6		$	197.2		$	1,119.8		$	—	$	—		$	1,119.8
Intersegment revenues	—			7.5			7.5			1.0		(8.5		)	—
Depreciation and amortization expense	60.5			11.4			71.9			0.5		(0.4		)	72.0
Miscellaneous income	1.4			0.1			1.5			9.9		—			11.4
Interest expense	24.4			5.9			30.3			1.6		—			31.9
Provision for income taxes	38.8			6.9			45.7			2.4		—			48.1
Preferred stock dividend requirements	(1.9		)	(0.4		)	(2.3		)	—		—			(2.3		)
Net income attributed to common shareholder	86.5			14.6			101.1			6.1		—			107.2