Segment Information (Tables)

12 Months Ended

Dec. 31, 2016

Segment Reporting [Abstract]

Schedule of information concerning our reportable segments

The following tables show summarized financial information related to our reportable segments for the years ended December 31, 2016, 2015, and 2014.

	Regulated Operations
2016 (in millions)	Wisconsin		Illinois		Other States		Electric Transmission		Total Regulated Operations		We Power		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
External revenues	$	5,805.4	$	1,242.2	$	376.5	$	—	$	7,424.1	$	24.9	$	23.3		$	—		$	7,472.3
Intersegment revenues	0.3		—		—		—		0.3		423.3		—			(423.6		)	—
Other operation and maintenance	2,025.4		485.1		110.1		—		2,620.6		4.3		(15.8		)	(423.6		)	2,185.5
Depreciation and amortization	496.6		134.0		21.1		—		651.7		68.3		42.6			—			762.6
Operating income (loss)	1,027.0		239.6		49.9		—		1,316.5		375.6		(10.0		)	—			1,682.1
Equity in earnings of transmission affiliate	—		—		—		146.5		146.5		—		—			—			146.5
Interest expense	180.9		38.9		8.5		—		228.3		62.1		120.9			(8.6		)	402.7
Capital expenditures	910.9		293.2		59.5		—		1,263.6		62.3		97.8			—			1,423.7
Total assets *	21,730.7		5,714.6		995.1		1,476.9		29,917.3		2,777.1		778.0			(3,349.2		)	30,123.2

* Total assets at December 31, 2016 reflect an elimination of $2,029.5 million for all lease activity between We Power and WE.

	Regulated Operations
2015 (in millions)	Wisconsin		Illinois		Other States		Electric Transmission		Total Regulated Operations		We Power		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
External revenues	$	5,186.1	$	503.4	$	149.3	$	—	$	5,838.8	$	40.0	$	47.3		$	—		$	5,926.1
Intersegment revenues	5.0		—		—		—		5.0		405.2		—			(410.2		)	—
Other operation and maintenance	1,741.0		219.6		50.0		—		2,010.6		4.3		103.7			(409.3		)	1,709.3
Depreciation and amortization	408.6		63.3		10.0		—		481.9		67.5		12.4			—			561.8
Operating income (loss)	884.2		78.1		6.0		—		968.3		373.4		(91.2		)	—			1,250.5
Equity in earnings of transmission affiliate	—		—		—		96.1		96.1		—		—			—			96.1
Interest expense	157.1		19.9		5.1		—		182.1		63.4		91.0			(5.1		)	331.4
Capital expenditures	950.3		194.4		34.7		—		1,179.4		53.4		33.4			—			1,266.2
Total assets *	21,113.5		5,462.9		918.0		1,381.0		28,875.4		2,779.0		1,132.5			(3,431.7		)	29,355.2

* Total assets at December 31, 2015 reflect an elimination of $2,105.3 million for all lease activity between We Power and WE.

	Regulated Operations
2014 (in millions)	Wisconsin		Illinois		Other States		Electric Transmission		Total Regulated Operations		We Power		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
External revenues	$	4,932.1	$	—	$	—	$	—	$	4,932.1	$	55.7	$	9.3		$	—		$	4,997.1
Intersegment revenues	9.2		—		—		—		9.2		383.4		—			(392.6		)	—
Other operation and maintenance	1,462.7		—		—		—		1,462.7		4.4		33.0			(387.7		)	1,112.4
Depreciation and amortization	323.2		—		—		—		323.2		66.7		1.5			—			391.4
Operating income (loss)	770.2		—		—		—		770.2		368.0		(26.1		)	—			1,112.1
Equity in earnings of transmission affiliate	—		—		—		66.0		66.0		—		—			—			66.0
Interest expense	127.6		—		—		—		127.6		64.6		48.8			(0.7		)	240.3
Capital expenditures	715.0		—		—		—		715.0		41.0		5.2			—			761.2
Total assets *	14,403.8		—		—		424.1		14,827.9		2,789.9		253.3			(2,966.1		)	14,905.0

* Total assets at December 31, 2014 reflect an elimination of $2,172.9 million for all lease activity between We Power and WE.