Segments Of Business (Tables)

3 Months Ended

Mar. 31, 2012

Schedule Of Segments Of Business

	Utility									Non-Regulated, Parent and  Other			Alliant  Energy Consolidated
	Electric		Gas		Other			Total
	(in millions)
Three Months Ended March 31, 2012
Operating revenues	$	572.4	$	167.1	$	13.7		$	753.2	$	12.5		$	765.7
Operating income		59.1		27.7		1.7			88.5		7.1			95.6
Amounts attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax									26.4		12.9			39.3
Loss from discontinued operations, net of tax									—		(4.4	)		(4.4	)
Net income attributable to Alliant Energy common shareowners									26.4		8.5			34.9
Three Months Ended March 31, 2011
Operating revenues		620.3		229.0		16.7			866.0		11.2			877.2
Operating income (loss)		89.3		35.9		(3.3	)		121.9		5.4			127.3
Amounts attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax									65.3		6.7			72.0
Income from discontinued operations, net of tax									—		1.5			1.5
Net income attributable to Alliant Energy common shareowners									65.3		8.2			73.5

IPL [Member]

Schedule Of Segments Of Business

	Electric		Gas		Other		Total
	(in millions)
Three Months Ended March 31, 2012
Operating revenues	$	293.1	$	92.8	$	12.8	$	398.7
Operating income		6.7		14.2		3.0		23.9
Earnings loss for common stock								(4.7	)
Three Months Ended March 31, 2011
Operating revenues		330.2		131.9		15.4		477.5
Operating income		27.9		15.8		3.4		47.1
Earnings available for common stock								21.7

WPL [Member]

Schedule Of Segments Of Business

	Electric		Gas		Other			Total
	(in millions)
Three Months Ended March 31, 2012
Operating revenues	$	279.3	$	74.3	$	0.9		$	354.5
Operating income (loss)		52.4		13.5		(1.3	)		64.6
Earnings available for common stock									31.1
Three Months Ended March 31, 2011
Operating revenues		290.1		97.1		1.3			388.5
Operating income (loss)		61.4		20.1		(6.7	)		74.8
Earnings available for common stock									43.6