Segment Information

9 Months Ended

Sep. 30, 2016

Segment Reporting [Abstract]

SEGMENT INFORMATION

SEGMENT INFORMATION

At September 30, 2016, we reported six segments, which are described below.

• The Wisconsin segment includes the electric and natural gas utility operations of WE, WG, and WPS, including WE's and WPS's electric and natural gas operations in the state of Michigan.

• The Illinois segment includes the natural gas utility and non-utility operations of PGL and NSG.

• The other states segment includes the natural gas utility and non-utility operations of MERC and MGU.

• The electric transmission segment includes our approximate 60% ownership interest in ATC, a for-profit, electric transmission company regulated by the FERC and certain state regulatory commissions.

• The We Power segment includes our nonregulated entity that owns and leases generating facilities to WE.

• The corporate and other segment includes the operations of the WEC Energy Group holding company, the Integrys holding company, the Peoples Energy, LLC holding company, Wispark LLC, Bostco LLC, Wisvest, Wisconsin Energy Capital Corporation, WBS, PDL, and ITF. The sale of ITF was completed in the first quarter of 2016. In the second quarter of 2016, we sold Wisvest's assets. See Note 3, Dispositions, for more information on these sales.

All of our operations are located within the United States. The following tables show summarized financial information related to our reportable segments for the three and nine months ended September 30, 2016 and 2015:

	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, 2016
External revenues	$	1,470.6	$	181.8	$	49.9		$	—	$	1,702.3	$	6.2	$	4.0		$	—		$	1,712.5
Intersegment revenues	—		—		—			—		—		105.0		—			(105.0		)	—
Other operation and maintenance	498.2		105.9		21.2			—		625.3		0.4		(3.2		)	(105.0		)	517.5
Depreciation and amortization	124.5		33.5		5.2			—		163.2		17.1		11.3			—			191.6
Operating income (loss)	299.1		11.7		(1.0		)	—		309.8		93.7		(4.5		)	—			399.0
Equity in earnings of transmission affiliate	—		—		—			38.3		38.3		—		—			—			38.3
Interest expense	44.6		9.3		1.9			—		55.8		15.6		29.7			(2.0		)	99.1

	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
External revenues	$	1,439.7	$	171.8	$	49.6		$	—	$	1,661.1	$	9.7	$	27.9		$	—		$	1,698.7
Intersegment revenues	2.6		—		—			—		2.6		101.0		—			(103.6		)	—
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		6.1			(0.1		)	176.5
Operating income (loss)	256.6		3.5		(3.7		)	—		256.4		93.2		(3.9		)	—			345.7
Equity in earnings of transmission affiliate	—		—		—			40.0		40.0		—		—			—			40.0
Interest expense	45.9		9.7		2.6			—		58.2		15.8		31.3			(2.1		)	103.2

	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, 2016
External revenues	$	4,354.9	$	853.1	$	262.3	$	—	$	5,470.3	$	18.7	$	20.3		$	—		$	5,509.3
Intersegment revenues	0.3		—		—		—		0.3		317.1		—			(317.4		)	—
Other operation and maintenance	1,477.3		340.0		80.6		—		1,897.9		3.5		(13.0		)	(317.4		)	1,571.0
Depreciation and amortization	370.1		99.4		15.5		—		485.0		51.1		33.4			—			569.5
Operating income (loss)	841.3		171.3		33.1		—		1,045.7		281.1		(6.4		)	—			1,320.4
Equity in earnings of transmission affiliate	—		—		—		107.7		107.7		—		—			—			107.7
Interest expense	133.5		28.8		6.5		—		168.8		46.8		91.2			(6.7		)	300.1

	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
External revenues	$	3,794.7	$	171.8	$	49.6		$	—	$	4,016.1	$	30.4	$	31.3		$	—		$	4,077.8
Intersegment revenues	4.4		—		—			—		4.4		302.7		—			(307.1		)	—
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 transmission affiliate	—		—		—			70.4		70.4		—		—			—			70.4
Interest expense	109.4		9.7		2.6			—		121.7		47.6		57.5			(2.4		)	224.4