Segments Of Business (Tables)

9 Months Ended

Sep. 30, 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,			Alliant
	Utility										Non-Utility,			Energy
	Electric		Gas			Other			Total		Parent and Other			Consolidated
	(in millions)
Three Months Ended September 30, 2018
Revenues		$861.2		$44.8			$12.3			$918.3		$10.3			$928.6
Operating income (loss)	248.7		(2.0		)	0.6			247.3		8.8			256.1
Net income attributable to Alliant Energy common shareowners									202.8		2.7			205.5
Three Months Ended September 30, 2017
Revenues		$840.6		$45.8			$11.2			$897.6		$9.3			$906.9
Operating income (loss)	236.7		(1.7		)	(7.7		)	227.3		9.0			236.3
Net income (loss) attributable to Alliant Energy common shareowners									170.2		(1.4		)	168.8

										ATC Holdings,		Alliant
	Utility									Non-Utility,		Energy
	Electric		Gas		Other			Total		Parent and Other		Consolidated
	(in millions)
Nine Months Ended September 30, 2018
Revenues		$2,296.2		$299.0		$36.2			$2,631.4		$29.6		$2,661.0
Operating income	510.2		34.9		2.9			548.0		25.0		573.0
Net income attributable to Alliant Energy common shareowners								395.0		31.8		426.8
Nine Months Ended September 30, 2017
Revenues		$2,199.1		$262.7		$34.4			$2,496.2		$29.9		$2,526.1
Operating income (loss)	486.9		31.3		(6.7		)	511.5		25.7		537.2
Amounts attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax								333.8		28.3		362.1
Income from discontinued operations, net of tax								—		1.4		1.4
Net income								333.8		29.7		363.5

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 September 30, 2018
Revenues		$509.2		$26.7			$11.7			$547.6
Operating income (loss)	144.7		(3.1		)	1.5			143.1
Earnings available for common stock									126.5
Three Months Ended September 30, 2017
Revenues		$489.0		$27.4			$11.0			$527.4
Operating income (loss)	140.0		(1.8		)	(4.4		)	133.8
Earnings available for common stock									120.4
Nine Months Ended September 30, 2018
Revenues		$1,337.0		$177.0			$34.2			$1,548.2
Operating income	275.7		16.3			4.4			296.4
Earnings available for common stock									224.9
Nine Months Ended September 30, 2017
Revenues		$1,217.6		$147.2			$33.3			$1,398.1
Operating income (loss)	239.2		15.4			(1.4		)	253.2
Earnings available for common stock									200.4

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 September 30, 2018
Revenues		$352.0		$18.1		$0.6			$370.7
Operating income (loss)	104.0		1.1		(0.9		)	104.2
Earnings available for common stock								76.3
Three Months Ended September 30, 2017
Revenues		$351.6		$18.4		$0.2			$370.2
Operating income (loss)	96.7		0.1		(3.3		)	93.5
Earnings available for common stock								49.8
Nine Months Ended September 30, 2018
Revenues		$959.2		$122.0		$2.0			$1,083.2
Operating income (loss)	234.5		18.6		(1.5		)	251.6
Earnings available for common stock								170.1
Nine Months Ended September 30, 2017
Revenues		$981.5		$115.5		$1.1			$1,098.1
Operating income (loss)	247.7		15.9		(5.3		)	258.3
Earnings available for common stock								133.4