Segments Of Business (Tables)

3 Months Ended

Mar. 31, 2018

Segment Reporting Information [Line Items]

Schedule Of Segments Of Business

Certain financial information relating to Alliant Energy’s business segments is as follows. Intersegment revenues were not material to Alliant Energy’s operations.

									ATC Holdings,
	Utility								Non-Utility,		Alliant Energy
	Electric		Gas		Other		Total		Parent and Other		Consolidated
	(in millions)
Three Months Ended March 31, 2018
Revenues		$708.7		$185.6		$13.2		$907.5		$8.8		$916.3
Operating income	126.7		31.5		1.4		159.6		6.1		165.7
Net income attributable to Alliant Energy common shareowners							100.7		20.2		120.9
Three Months Ended March 31, 2017
Revenues		$677.6		$154.3		$11.7		$843.6		$10.3		$853.9
Operating income	110.9		28.6		0.4		139.9		7.3		147.2
Amounts attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax							82.7		16.3		99.0
Income from discontinued operations, net of tax							—		1.4		1.4
Net income							82.7		17.7		100.4

IPL [Member]

Segment Reporting Information [Line Items]

Schedule Of Segments Of Business

Certain financial information relating to IPL’s business segments is as follows. Intersegment revenues were not material to IPL’s operations.

	Electric		Gas		Other		Total
	(in millions)
Three Months Ended March 31, 2018
Revenues		$405.7		$108.1		$12.0		$525.8
Operating income	57.5		16.9		1.2		75.6
Earnings available for common stock							46.7
Three Months Ended March 31, 2017
Revenues		$356.2		$83.1		$11.2		$450.5
Operating income	35.3		14.6		1.4		51.3
Earnings available for common stock							37.2

WPL [Member]

Segment Reporting Information [Line Items]

Schedule Of Segments Of Business

Certain financial information relating to WPL’s business segments is as follows. Intersegment revenues were not material to WPL’s operations.

	Electric		Gas		Other			Total
	(in millions)
Three Months Ended March 31, 2018
Revenues		$303.0		$77.5		$1.2			$381.7
Operating income	69.2		14.6		0.2			84.0
Earnings available for common stock								54.0
Three Months Ended March 31, 2017
Revenues		$321.4		$71.2		$0.5			$393.1
Operating income (loss)	75.6		14.0		(1.0		)	88.6
Earnings available for common stock								45.5