Segments Of Business

9 Months Ended

Sep. 30, 2017

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. Refer to Note 5(a) for discussion of Alliant Energy’s acquisition of an interest in a non-regulated wind farm in Oklahoma in July 2017, which increased the assets for “Non-Regulated, Parent and Other.” Refer to Note 3 for discussion of asset valuation charges recorded in the third quarter of 2016 related to the Franklin County wind farm.

	Utility (a)										Non-Regulated,			Alliant Energy
	Electric		Gas			Other			Total		Parent and Other			Consolidated
	(in millions)
Three Months Ended September 30, 2017
Operating revenues		$840.6		$45.8			$11.2			$897.6		$9.3			$906.9
Operating income (loss)	232.6		(2.4		)	(7.7		)	222.5		9.0			231.5
Net income (loss) attributable to Alliant Energy common shareowners									176.3		(7.5		)	168.8
Three Months Ended September 30, 2016
Operating revenues		$864.3		$39.5			$9.4			$913.2		$11.4			$924.6
Operating income (loss)	244.2		(3.7		)	0.4			240.9		(78.3		)	162.6
Amounts attributable to Alliant Energy common shareowners:
Income (loss) from continuing operations, net of tax									183.1		(54.3		)	128.8
Loss from discontinued operations, net of tax									—		(0.4		)	(0.4		)
Net income (loss)									183.1		(54.7		)	128.4

	Utility (a)									Non-Regulated,			Alliant Energy
	Electric		Gas		Other			Total		Parent and Other			Consolidated
	(in millions)
Nine Months Ended September 30, 2017
Operating revenues		$2,199.1		$262.7		$34.4			$2,496.2		$29.9			$2,526.1
Operating income (loss)	475.4		29.5		(6.8		)	498.1		25.6			523.7
Amounts attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax								353.5		8.6			362.1
Income from discontinued operations, net of tax								—		1.4			1.4
Net income								353.5		10.0			363.5
Nine Months Ended September 30, 2016
Operating revenues		$2,209.1		$248.7		$35.0			$2,492.8		$30.2			$2,523.0
Operating income (loss)	473.3		27.0		4.4			504.7		(67.6		)	437.1
Amounts attributable to Alliant Energy common shareowners:
Income (loss) from continuing operations, net of tax								350.3		(39.5		)	310.8
Loss from discontinued operations, net of tax								—		(2.0		)	(2.0		)
Net income (loss)								350.3		(41.5		)	308.8

(a) Alliant Energy’s utility business segments include: a) utility electric operations, which include Alliant Energy’s entire investment in ATC; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business.

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, 2017
Operating revenues		$489.0		$27.4			$11.0			$527.4
Operating income (loss)	138.3		(2.1		)	(4.4		)	131.8
Earnings available for common stock									120.4
Three Months Ended September 30, 2016
Operating revenues		$483.2		$23.9			$9.1			$516.2
Operating income (loss)	125.9		(1.4		)	1.4			125.9
Earnings available for common stock									114.1
Nine Months Ended September 30, 2017
Operating revenues		$1,217.6		$147.2			$33.3			$1,398.1
Operating income (loss)	234.5		14.7			(1.5		)	247.7
Earnings available for common stock									200.4
Nine Months Ended September 30, 2016
Operating revenues		$1,209.2		$142.6			$34.1			$1,385.9
Operating income	213.8		15.3			6.8			235.9
Earnings available for common stock									191.6

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, 2017
Operating revenues		$351.6		$18.4			$0.2			$370.2
Operating income (loss)	94.3		(0.3		)	(3.3		)	90.7
Earnings available for common stock									49.8
Three Months Ended September 30, 2016
Operating revenues		$381.1		$15.6			$0.3			$397.0
Operating income (loss)	118.3		(2.3		)	(1.0		)	115.0
Earnings available for common stock									69.0
Nine Months Ended September 30, 2017
Operating revenues		$981.5		$115.5			$1.1			$1,098.1
Operating income (loss)	240.9		14.8			(5.3		)	250.4
Earnings available for common stock									133.4
Nine Months Ended September 30, 2016
Operating revenues		$999.9		$106.1			$0.9			$1,106.9
Operating income (loss)	259.5		11.7			(2.4		)	268.8
Earnings available for common stock									158.7

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. Refer to Note 5(a) for discussion of Alliant Energy’s acquisition of an interest in a non-regulated wind farm in Oklahoma in July 2017, which increased the assets for “Non-Regulated, Parent and Other.” Refer to Note 3 for discussion of asset valuation charges recorded in the third quarter of 2016 related to the Franklin County wind farm.

	Utility (a)										Non-Regulated,			Alliant Energy
	Electric		Gas			Other			Total		Parent and Other			Consolidated
	(in millions)
Three Months Ended September 30, 2017
Operating revenues		$840.6		$45.8			$11.2			$897.6		$9.3			$906.9
Operating income (loss)	232.6		(2.4		)	(7.7		)	222.5		9.0			231.5
Net income (loss) attributable to Alliant Energy common shareowners									176.3		(7.5		)	168.8
Three Months Ended September 30, 2016
Operating revenues		$864.3		$39.5			$9.4			$913.2		$11.4			$924.6
Operating income (loss)	244.2		(3.7		)	0.4			240.9		(78.3		)	162.6
Amounts attributable to Alliant Energy common shareowners:
Income (loss) from continuing operations, net of tax									183.1		(54.3		)	128.8
Loss from discontinued operations, net of tax									—		(0.4		)	(0.4		)
Net income (loss)									183.1		(54.7		)	128.4

	Utility (a)									Non-Regulated,			Alliant Energy
	Electric		Gas		Other			Total		Parent and Other			Consolidated
	(in millions)
Nine Months Ended September 30, 2017
Operating revenues		$2,199.1		$262.7		$34.4			$2,496.2		$29.9			$2,526.1
Operating income (loss)	475.4		29.5		(6.8		)	498.1		25.6			523.7
Amounts attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax								353.5		8.6			362.1
Income from discontinued operations, net of tax								—		1.4			1.4
Net income								353.5		10.0			363.5
Nine Months Ended September 30, 2016
Operating revenues		$2,209.1		$248.7		$35.0			$2,492.8		$30.2			$2,523.0
Operating income (loss)	473.3		27.0		4.4			504.7		(67.6		)	437.1
Amounts attributable to Alliant Energy common shareowners:
Income (loss) from continuing operations, net of tax								350.3		(39.5		)	310.8
Loss from discontinued operations, net of tax								—		(2.0		)	(2.0		)
Net income (loss)								350.3		(41.5		)	308.8

(a) Alliant Energy’s utility business segments include: a) utility electric operations, which include Alliant Energy’s entire investment in ATC; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business.

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, 2017
Operating revenues		$489.0		$27.4			$11.0			$527.4
Operating income (loss)	138.3		(2.1		)	(4.4		)	131.8
Earnings available for common stock									120.4
Three Months Ended September 30, 2016
Operating revenues		$483.2		$23.9			$9.1			$516.2
Operating income (loss)	125.9		(1.4		)	1.4			125.9
Earnings available for common stock									114.1
Nine Months Ended September 30, 2017
Operating revenues		$1,217.6		$147.2			$33.3			$1,398.1
Operating income (loss)	234.5		14.7			(1.5		)	247.7
Earnings available for common stock									200.4
Nine Months Ended September 30, 2016
Operating revenues		$1,209.2		$142.6			$34.1			$1,385.9
Operating income	213.8		15.3			6.8			235.9
Earnings available for common stock									191.6

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, 2017
Operating revenues		$351.6		$18.4			$0.2			$370.2
Operating income (loss)	94.3		(0.3		)	(3.3		)	90.7
Earnings available for common stock									49.8
Three Months Ended September 30, 2016
Operating revenues		$381.1		$15.6			$0.3			$397.0
Operating income (loss)	118.3		(2.3		)	(1.0		)	115.0
Earnings available for common stock									69.0
Nine Months Ended September 30, 2017
Operating revenues		$981.5		$115.5			$1.1			$1,098.1
Operating income (loss)	240.9		14.8			(5.3		)	250.4
Earnings available for common stock									133.4
Nine Months Ended September 30, 2016
Operating revenues		$999.9		$106.1			$0.9			$1,106.9
Operating income (loss)	259.5		11.7			(2.4		)	268.8
Earnings available for common stock									158.7

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. Refer to Note 5(a) for discussion of Alliant Energy’s acquisition of an interest in a non-regulated wind farm in Oklahoma in July 2017, which increased the assets for “Non-Regulated, Parent and Other.” Refer to Note 3 for discussion of asset valuation charges recorded in the third quarter of 2016 related to the Franklin County wind farm.

	Utility (a)										Non-Regulated,			Alliant Energy
	Electric		Gas			Other			Total		Parent and Other			Consolidated
	(in millions)
Three Months Ended September 30, 2017
Operating revenues		$840.6		$45.8			$11.2			$897.6		$9.3			$906.9
Operating income (loss)	232.6		(2.4		)	(7.7		)	222.5		9.0			231.5
Net income (loss) attributable to Alliant Energy common shareowners									176.3		(7.5		)	168.8
Three Months Ended September 30, 2016
Operating revenues		$864.3		$39.5			$9.4			$913.2		$11.4			$924.6
Operating income (loss)	244.2		(3.7		)	0.4			240.9		(78.3		)	162.6
Amounts attributable to Alliant Energy common shareowners:
Income (loss) from continuing operations, net of tax									183.1		(54.3		)	128.8
Loss from discontinued operations, net of tax									—		(0.4		)	(0.4		)
Net income (loss)									183.1		(54.7		)	128.4

	Utility (a)									Non-Regulated,			Alliant Energy
	Electric		Gas		Other			Total		Parent and Other			Consolidated
	(in millions)
Nine Months Ended September 30, 2017
Operating revenues		$2,199.1		$262.7		$34.4			$2,496.2		$29.9			$2,526.1
Operating income (loss)	475.4		29.5		(6.8		)	498.1		25.6			523.7
Amounts attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax								353.5		8.6			362.1
Income from discontinued operations, net of tax								—		1.4			1.4
Net income								353.5		10.0			363.5
Nine Months Ended September 30, 2016
Operating revenues		$2,209.1		$248.7		$35.0			$2,492.8		$30.2			$2,523.0
Operating income (loss)	473.3		27.0		4.4			504.7		(67.6		)	437.1
Amounts attributable to Alliant Energy common shareowners:
Income (loss) from continuing operations, net of tax								350.3		(39.5		)	310.8
Loss from discontinued operations, net of tax								—		(2.0		)	(2.0		)
Net income (loss)								350.3		(41.5		)	308.8

(a) Alliant Energy’s utility business segments include: a) utility electric operations, which include Alliant Energy’s entire investment in ATC; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business.

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, 2017
Operating revenues		$489.0		$27.4			$11.0			$527.4
Operating income (loss)	138.3		(2.1		)	(4.4		)	131.8
Earnings available for common stock									120.4
Three Months Ended September 30, 2016
Operating revenues		$483.2		$23.9			$9.1			$516.2
Operating income (loss)	125.9		(1.4		)	1.4			125.9
Earnings available for common stock									114.1
Nine Months Ended September 30, 2017
Operating revenues		$1,217.6		$147.2			$33.3			$1,398.1
Operating income (loss)	234.5		14.7			(1.5		)	247.7
Earnings available for common stock									200.4
Nine Months Ended September 30, 2016
Operating revenues		$1,209.2		$142.6			$34.1			$1,385.9
Operating income	213.8		15.3			6.8			235.9
Earnings available for common stock									191.6

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, 2017
Operating revenues		$351.6		$18.4			$0.2			$370.2
Operating income (loss)	94.3		(0.3		)	(3.3		)	90.7
Earnings available for common stock									49.8
Three Months Ended September 30, 2016
Operating revenues		$381.1		$15.6			$0.3			$397.0
Operating income (loss)	118.3		(2.3		)	(1.0		)	115.0
Earnings available for common stock									69.0
Nine Months Ended September 30, 2017
Operating revenues		$981.5		$115.5			$1.1			$1,098.1
Operating income (loss)	240.9		14.8			(5.3		)	250.4
Earnings available for common stock									133.4
Nine Months Ended September 30, 2016
Operating revenues		$999.9		$106.1			$0.9			$1,106.9
Operating income (loss)	259.5		11.7			(2.4		)	268.8
Earnings available for common stock									158.7