SEGMENT INFORMATION (Tables)

3 Months Ended

Mar. 31, 2017

Segment Reporting [Abstract]

Financial information of reportable segments

The following tables show summarized financial information related to our reportable segments for the three months ended March 31, 2017 and 2016:

	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
March 31, 2017
External revenues	$	1,612.1	$	525.3	$	157.9	$	—	$	2,295.3	$	6.3	$	2.9		$	—		$	2,304.5
Intersegment revenues	—		—		—		—		—		109.0		—			(109.0		)	—
Other operation and maintenance	462.9		120.9		28.3		—		612.1		0.4		(1.6		)	(109.0		)	501.9
Depreciation and amortization	129.3		36.2		6.0		—		171.5		17.5		5.6			—			194.6
Operating income (loss)	332.3		155.4		33.4		—		521.1		97.4		(1.2		)	—			617.3
Equity in earnings of transmission affiliate	—		—		—		41.9		41.9		—		—			—			41.9
Interest expense	48.7		11.1		2.3		—		62.1		15.3		29.1			(1.8		)	104.7

	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
March 31, 2016
External revenues	$	1,579.8	$	448.5	$	148.4	$	—	$	2,176.7	$	6.2	$	11.9		$	—		$	2,194.8
Intersegment revenues	0.1		—		—		—		0.1		104.5		—			(104.6		)	—
Other operation and maintenance	491.3		117.9		30.0		—		639.2		0.4		(3.5		)	(104.6		)	531.5
Depreciation and amortization	122.9		32.8		5.1		—		160.8		17.0		10.1			—			187.9
Operating income (loss)	327.5		137.0		31.8		—		496.3		93.3		(0.3		)	—			589.3
Equity in earnings of transmission affiliate	—		—		—		38.5		38.5		—		—			—			38.5
Interest expense	44.5		9.7		2.5		—		56.7		15.6		31.3			(2.7		)	100.9