SEGMENT INFORMATION (Tables)

6 Months Ended

Jun. 30, 2019

Segment Reporting [Abstract]

Financial information of reportable segments

The following tables show summarized financial information related to our reportable segments for the three and six months ended June 30, 2019 and 2018:

	Utility Operations
(in millions)	Wisconsin		Illinois		Other States		Total Utility Operations		Electric Transmission		Non-Utility Energy Infrastructure		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
Three Months Ended
June 30, 2019
External revenues	$	1,253.3	$	242.9	$	68.8	$	1,565.0	$	—	$	24.3	$	0.9		$	—		$	1,590.2
Intersegment revenues	—		—		—		—		—		99.0		—			(99.0		)	—
Other operation and maintenance	363.9		107.0		23.4		494.3		—		6.8		1.8			0.7			503.6
Depreciation and amortization	152.9		45.0		6.7		204.6		—		22.9		6.0			(3.6		)	229.9
Operating income (loss)	270.2		42.6		4.6		317.4		—		91.3		(7.1		)	(87.0		)	314.6
Equity in earnings of transmission affiliates	—		—		—		—		36.9		—		—			—			36.9
Interest expense	142.7		13.9		1.9		158.5		2.7		15.5		36.5			(89.1		)	124.1

	Utility Operations
(in millions)	Wisconsin		Illinois		Other States		Total Utility Operations		Electric Transmission		Non-Utility Energy Infrastructure		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
Three Months Ended
June 30, 2018
External revenues	$	1,325.5	$	268.0	$	72.4	$	1,665.9	$	—	$	3.5	$	3.1		$	—		$	1,672.5
Intersegment revenues	—		—		—		—		—		113.5		—			(113.5		)	—
Other operation and maintenance	502.4		104.1		24.9		631.4		—		4.5		2.2			(100.4		)	537.7
Depreciation and amortization	134.6		41.8		4.5		180.9		—		18.3		7.5			—			206.7
Operating income (loss)	195.1		41.7		8.1		244.9		—		92.4		(6.5		)	—			330.8
Equity in earnings of transmission affiliates	—		—		—		—		28.7		—		—			—			28.7
Interest expense	48.5		12.3		2.1		62.9		—		16.0		30.3			(0.7		)	108.5

	Utility Operations
(in millions)	Wisconsin		Illinois		Other States		Total Utility Operations		Electric Transmission		Non-Utility Energy Infrastructure		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
Six Months Ended
June 30, 2019
External revenues	$	2,886.7	$	779.4	$	254.0	$	3,920.1	$	—	$	44.9	$	2.6		$	—		$	3,967.6
Intersegment revenues	—		—		—		—		—		206.2		—			(206.2		)	—
Other operation and maintenance	756.6		235.2		51.0		1,042.8		—		10.6		0.8			—			1,054.2
Depreciation and amortization	303.9		89.5		13.2		406.6		—		45.5		12.4			(8.2		)	456.3
Operating income (loss)	632.0		180.5		46.1		858.6		—		184.0		(11.0		)	(174.2		)	857.4
Equity in earnings of transmission affiliates	—		—		—		—		73.0		—		—			—			73.0
Interest expense	286.1		28.7		4.2		319.0		5.3		31.2		71.6			(178.6		)	248.5

	Utility Operations
(in millions)	Wisconsin		Illinois		Other States		Total Utility Operations		Electric Transmission		Non-Utility Energy Infrastructure		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
Six Months Ended
June 30, 2018
External revenues	$	2,914.6	$	775.3	$	242.3	$	3,932.2	$	—	$	22.3	$	4.5		$	—		$	3,959.0
Intersegment revenues	—		—		—		—		—		212.8		—			(212.8		)	—
Other operation and maintenance	970.9		216.3		51.5		1,238.7		—		6.2		1.9			(197.2		)	1,049.6
Depreciation and amortization	269.7		82.7		11.1		363.5		—		36.6		15.2			—			415.3
Operating income (loss)	468.8		189.3		44.3		702.4		—		185.4		(11.9		)	—			875.9
Equity in earnings of transmission affiliates	—		—		—		—		61.5		—		—			—			61.5
Interest expense	97.9		24.6		4.2		126.7		—		32.1		58.3			(1.9		)	215.2