Segments Of Business

9 Months Ended

Sep. 30, 2019

Segment Reporting Information [Line Items]

Segments Of Business

SEGMENTS OF BUSINESS

Alliant Energy - 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, 2019
Revenues		$915.9		$41.5			$11.2		$968.6		$21.6		$990.2
Operating income (loss)	283.7		(4.7		)	2.8		281.8		8.4		290.2
Net income attributable to Alliant Energy common shareowners								216.6		9.4		226.0
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

									ATC Holdings,		Alliant
	Utility								Non-Utility,		Energy
	Electric		Gas		Other		Total		Parent and Other		Consolidated
	(in millions)
Nine Months Ended September 30, 2019
Revenues		$2,350.5		$322.5		$33.2		$2,706.2		$61.4		$2,767.6
Operating income	543.0		47.7		4.2		594.9		21.9		616.8
Net income attributable to Alliant Energy common shareowners							422.6		23.1		445.7
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

IPL - 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, 2019
Revenues		$560.9		$24.8			$10.8		$596.5
Operating income (loss)	175.1		(4.2		)	2.6		173.5
Earnings available for common stock								141.1
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
Nine Months Ended September 30, 2019
Revenues		$1,373.0		$187.8			$32.0		$1,592.8
Operating income	290.8		26.3			4.4		321.5
Earnings available for common stock								239.4
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

WPL - 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, 2019
Revenues		$355.0		$16.7			$0.4			$372.1
Operating income (loss)	108.6		(0.5		)	0.2			108.3
Earnings available for common stock									75.5
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
Nine Months Ended September 30, 2019
Revenues		$977.5		$134.7			$1.2			$1,113.4
Operating income (loss)	252.2		21.4			(0.2		)	273.4
Earnings available for common stock									183.2
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

IPL [Member]

Segment Reporting Information [Line Items]

Segments Of Business

SEGMENTS OF BUSINESS

Alliant Energy - 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, 2019
Revenues		$915.9		$41.5			$11.2		$968.6		$21.6		$990.2
Operating income (loss)	283.7		(4.7		)	2.8		281.8		8.4		290.2
Net income attributable to Alliant Energy common shareowners								216.6		9.4		226.0
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

									ATC Holdings,		Alliant
	Utility								Non-Utility,		Energy
	Electric		Gas		Other		Total		Parent and Other		Consolidated
	(in millions)
Nine Months Ended September 30, 2019
Revenues		$2,350.5		$322.5		$33.2		$2,706.2		$61.4		$2,767.6
Operating income	543.0		47.7		4.2		594.9		21.9		616.8
Net income attributable to Alliant Energy common shareowners							422.6		23.1		445.7
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

IPL - 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, 2019
Revenues		$560.9		$24.8			$10.8		$596.5
Operating income (loss)	175.1		(4.2		)	2.6		173.5
Earnings available for common stock								141.1
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
Nine Months Ended September 30, 2019
Revenues		$1,373.0		$187.8			$32.0		$1,592.8
Operating income	290.8		26.3			4.4		321.5
Earnings available for common stock								239.4
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

WPL - 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, 2019
Revenues		$355.0		$16.7			$0.4			$372.1
Operating income (loss)	108.6		(0.5		)	0.2			108.3
Earnings available for common stock									75.5
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
Nine Months Ended September 30, 2019
Revenues		$977.5		$134.7			$1.2			$1,113.4
Operating income (loss)	252.2		21.4			(0.2		)	273.4
Earnings available for common stock									183.2
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

WPL [Member]

Segment Reporting Information [Line Items]

Segments Of Business

SEGMENTS OF BUSINESS

Alliant Energy - 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, 2019
Revenues		$915.9		$41.5			$11.2		$968.6		$21.6		$990.2
Operating income (loss)	283.7		(4.7		)	2.8		281.8		8.4		290.2
Net income attributable to Alliant Energy common shareowners								216.6		9.4		226.0
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

									ATC Holdings,		Alliant
	Utility								Non-Utility,		Energy
	Electric		Gas		Other		Total		Parent and Other		Consolidated
	(in millions)
Nine Months Ended September 30, 2019
Revenues		$2,350.5		$322.5		$33.2		$2,706.2		$61.4		$2,767.6
Operating income	543.0		47.7		4.2		594.9		21.9		616.8
Net income attributable to Alliant Energy common shareowners							422.6		23.1		445.7
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

IPL - 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, 2019
Revenues		$560.9		$24.8			$10.8		$596.5
Operating income (loss)	175.1		(4.2		)	2.6		173.5
Earnings available for common stock								141.1
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
Nine Months Ended September 30, 2019
Revenues		$1,373.0		$187.8			$32.0		$1,592.8
Operating income	290.8		26.3			4.4		321.5
Earnings available for common stock								239.4
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

WPL - 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, 2019
Revenues		$355.0		$16.7			$0.4			$372.1
Operating income (loss)	108.6		(0.5		)	0.2			108.3
Earnings available for common stock									75.5
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
Nine Months Ended September 30, 2019
Revenues		$977.5		$134.7			$1.2			$1,113.4
Operating income (loss)	252.2		21.4			(0.2		)	273.4
Earnings available for common stock									183.2
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