Segment Information (Tables)

9 Months Ended

Sep. 30, 2015

Segment Information [Abstract]

Financial information of reportable operating segments

Summarized financial information concerning our reportable segments for the three and nine months ended September 30, 2015 and 2014, is shown in the following tables:

	Regulated Operations
(in millions)	Wisconsin		Illinois		Other States			Electric Transmission		Total Regulated Operations		We Power		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
Three Months Ended
September 30, 2015
Operating revenues	$	1,442.3	$	171.8	$	49.6		$	—	$	1,663.7	$	110.7	$	27.9		$	(103.6	)	$	1,698.7
Other operation and maintenance	501.9		101.0		23.1			—		626.0		0.6		12.9			(103.6		)	535.9
Depreciation and amortization	117.5		31.2		4.9			—		153.6		16.9		6.0			—			176.5
Operating income (loss)	256.6		3.5		(3.7		)	—		256.4		93.2		(3.9		)	—			345.7
Equity in earnings of unconsolidated affiliates	0.2		—		—			40.0		40.2		—		(0.3		)	0.1			40.0
Interest expense	46.5		9.7		2.6			—		58.8		15.8		31.6			(2.4		)	103.8

	Regulated Operations
(in millions)	Wisconsin		Illinois		Other States		Electric Transmission		Total Regulated Operations		We Power		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
Three Months Ended
September 30, 2014
Operating revenues	$	1,017.7	$	—	$	—	$	—	$	1,017.7	$	109.0	$	5.3		$	(98.7	)	$	1,033.3
Other operation and maintenance	337.4		—		—		—		337.4		0.4		9.0			(97.4		)	249.4
Depreciation and amortization	82.8		—		—		—		82.8		16.7		0.4			(0.1		)	99.8
Operating income (loss)	158.4		—		—		—		158.4		92.0		(4.3		)	—			246.1
Equity in earnings of unconsolidated affiliates	—		—		—		18.0		18.0		—		—			—			18.0
Interest expense	32.1		—		—		—		32.1		16.1		12.4			(0.2		)	60.4

	Regulated Operations
(in millions)	Wisconsin		Illinois		Other States			Electric Transmission		Total Regulated Operations		We Power		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
Nine Months Ended
September 30, 2015
Operating revenues	$	3,799.1	$	171.8	$	49.6		$	—	$	4,020.5	$	333.1	$	31.3		$	(307.1	)	$	4,077.8
Other operation and maintenance	1,239.3		101.0		23.1			—		1,363.4		3.7		93.1			(306.6		)	1,153.6
Depreciation and amortization	289.2		31.2		4.9			—		325.3		50.6		6.8			(0.1		)	382.6
Operating income (loss)	673.5		3.5		(3.7		)	—		673.3		278.9		(81.9		)	—			870.3
Equity in earnings of unconsolidated affiliates	0.2		—		—			70.4		70.6		—		(0.4		)	0.2			70.4
Interest expense	110.6		9.7		2.6			—		122.9		47.6		57.5			(2.4		)	225.6

	Regulated Operations
(in millions)	Wisconsin		Illinois		Other States		Electric Transmission		Total Regulated Operations		We Power		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
Nine Months Ended
September 30, 2014
Operating revenues	$	3,729.6	$	—	$	—	$	—	$	3,729.6	$	328.1	$	8.6		$	(294.3	)	$	3,772.0
Other operation and maintenance	1,048.6		—		—		—		1,048.6		3.6		19.1			(290.5		)	780.8
Depreciation and amortization	244.1		—		—		—		244.1		49.9		1.2			—			295.2
Operating income (loss)	606.3		—		—		—		606.3		274.6		(12.3		)	—			868.6
Equity in earnings of unconsolidated affiliates	—		—		—		52.8		52.8		—		—			—			52.8
Interest expense	96.8		—		—		—		96.8		48.6		36.8			(0.5		)	181.7