Segment Information (Tables)

12 Months Ended

Dec. 31, 2015

Segment Reporting [Abstract]

Schedule of information concerning our reportable segments

The following tables show summarized financial information concerning our reportable segments for the years ended December 31, 2015, 2014, and 2013.

	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 PTF activity between We Power and Wisconsin Electric.

	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 PTF activity between We Power and Wisconsin Electric.

	Regulated Operations
2013 (in millions)	Wisconsin		Illinois		Other States		Electric Transmission		Total Regulated Operations		We Power		Corporate and Other			Reconciling Eliminations			WEC Energy Group Consolidated
External revenues	$	4,451.9	$	—	$	—	$	—	$	4,451.9	$	56.6	$	10.5		$	—		$	4,519.0
Intersegment revenues	10.1		—		—		—		10.1		380.9		—			(391.0		)	—
Other operation and maintenance	1,522.0		—		—		—		1,522.0		4.6		14.2			(385.8		)	1,155.0
Depreciation and amortization	272.2		—		—		—		272.2		66.3		1.6			—			340.1
Operating income	719.4		—		—		—		719.4		366.6		(5.9		)	—			1,080.1
Equity in earnings of transmission affiliate	—		—		—		68.5		68.5		—		—			—			68.5
Interest expense	135.0		—		—		—		135.0		65.7		50.8			(0.6		)	250.9
Capital expenditures	695.7		—		—		—		695.7		25.8		3.7			—			725.2
Total assets *	13,934.6		—		—		402.7		14,337.3		2,814.6		213.6			(2,922.3		)	14,443.2

* Total assets at December 31, 2013 reflect an elimination of $2,231.2 million for all PTF activity between We Power and Wisconsin Electric.