Segments Of Business (Tables)

12 Months Ended

Dec. 31, 2011

Schedule Of Segments Of Business

	Utility											Non- Regulated- RMT (a)			Other Non- Regulated, Parent and Other			Alliant Energy Consolidated
	Electric			Gas		Other			Total
2011
Operating revenues	$	2,635.8		$	476.7	$	62.0		$	3,174.5		$	443.9		$	46.9		$	3,665.3
Depreciation and amortization		289.0			28.4		1.8			319.2			2.8			1.8			323.8
Operating income (loss)		444.2			47.8		(3.2	)		488.8			(34.9	)		24.5			478.4
Interest expense, net of AFUDC										146.6			1.4			(1.7	)		146.3
Equity income from unconsolidated investments, net		(38.7	)		—		—			(38.7	)		—			(0.6	)		(39.3	)
Interest income and other										(0.2	)		(1.4	)		(2.7	)		(4.3	)
Income tax expense (benefit)										78.3			(14.1	)		(9.1	)		55.1
Income (loss) from continuing operations, net of tax										302.8			(20.8	)		38.6			320.6
Income from discontinued operations, net of tax										—			—			1.3			1.3
Net income (loss)										302.8			(20.8	)		39.9			321.9
Preferred dividends										18.3			—			—			18.3
Net income (loss) attributable to Alliant Energy common shareowners										284.5			(20.8	)		39.9			303.6
Total assets		7,524.5			831.9		781.1			9,137.5			126.3			424.1			9,687.9
Investments in equity method subsidiaries		246.5			—		—			246.5			—			3.1			249.6
Construction and acquisition expenditures		542.7			38.0		27.4			608.1			0.7			64.6			673.4

	Utility											Non- Regulated- RMT (a)			Other Non- Regulated, Parent and Other			Alliant Energy Consolidated
	Electric			Gas		Other			Total
2010
Operating revenues	$	2,674.2		$	480.6	$	64.6		$	3,219.4		$	154.0		$	42.7		$	3,416.1
Depreciation and amortization		255.1			25.2		5.3			285.6			4.0			1.7			291.3
Operating income (loss)		489.8			53.4		(2.5	)		540.7			(3.9	)		19.3			556.1
Interest expense, net of AFUDC										142.8			0.2			2.0			145.0
Equity income from unconsolidated investments, net		(37.8	)		—		—			(37.8	)		—			(0.3	)		(38.1	)
Interest income and other										(0.6	)		0.6			(4.0	)		(4.0	)
Income tax expense (benefit)										140.6			(2.5	)		7.1			145.2
Income (loss) from continuing operations, net of tax										295.7			(2.2	)		14.5			308.0
Loss from discontinued operations, net of tax										—			—			(1.7	)		(1.7	)
Net income (loss)										295.7			(2.2	)		12.8			306.3
Preferred dividends										18.7			—			—			18.7
Net income (loss) attributable to Alliant Energy common shareowners										277.0			(2.2	)		12.8			287.6
Total assets		7,227.2			817.6		782.4			8,827.2			90.7			365.0			9,282.9
Investments in equity method subsidiaries		236.0			—		—			236.0			—			2.5			238.5
Construction and acquisition expenditures		729.1			39.9		64.3			833.3			1.4			32.2			866.9

	Utility											Non- Regulated- RMT			Other Non- Regulated, Parent and Other			Alliant Energy Consolidated
	Electric			Gas		Other			Total
2009
Operating revenues	$	2,475.9		$	525.3	$	92.9		$	3,094.1		$	294.1		$	39.1		$	3,427.3
Depreciation and amortization		233.5			25.8		8.9			268.2			2.4			3.0			273.6
Operating income (loss)		342.2			52.3		(5.8	)		388.7			(4.9	)		12.4			396.2
Interest expense, net of AFUDC										111.6			0.2			3.4			115.2
Loss on early extinguishment of debt										—			—			203.0			203.0
Equity (income) loss from unconsolidated investments, net		(37.0	)		—		—			(37.0	)		—			0.4			(36.6	)
Interest income and other										(1.2	)		(1.1	)		(2.6	)		(4.9	)
Income tax expense (benefit)										72.8			(2.5	)		(79.6	)		(9.3	)
Income (loss) from continuing operations, net of tax										242.5			(1.5	)		(112.2	)		128.8
Income from discontinued operations, net of tax										—			—			0.9			0.9
Net income (loss)										242.5			(1.5	)		(111.3	)		129.7
Preferred dividends										18.7			—			—			18.7
Net income (loss) attributable to Alliant Energy common shareowners										223.8			(1.5	)		(111.3	)		111.0
Total assets		6,867.6			803.1		902.9			8,573.6			63.6			398.8			9,036.0
Investments in equity method subsidiaries		227.1			—		—			227.1			—			2.1			229.2
Construction and acquisition expenditures		1,191.8			45.2		5.0			1,242.0			8.2			(47.6	)		1,202.6

(a) RMT's operating revenues and expenses increased significantly in 2011 primarily due to increased demand for construction management services for large wind and solar projects. RMT's operating loss and net loss in 2011 was largely driven by losses associated with certain large solar projects as a result of issues with certain of its subcontractors engaged to complete the solar projects. Schedule delays, abandonment of work by the original subcontractor and the need to hire additional subcontractors to complete the work in a timely manner resulted in significant additional costs for RMT in 2011.

Products And Services

	2011			2010			2009
Utility electric operations		72	%		78	%		72	%
Utility gas operations		13	%		14	%		15	%
Utility other		2	%		2	%		3	%
Non-regulated - RMT		12	%		5	%		9	%
Other		1	%		1	%		1	%
		100	%		100	%		100	%

IPL [Member]

Schedule Of Segments Of Business

		Electric		Gas		Other		Total
2011
Operating revenues	$	1,408.3	$	276.3	$	55.5	$	1,740.1
Depreciation and amortization		161.3		16.0		1.8		179.1
Operating income		181.6		20.6		6.2		208.4
Interest expense, net of AFUDC								72.9
Interest income and other								(0.2	)
Income tax benefit								(3.6	)
Net income								139.3
Preferred dividends								15.0
Earnings available for common stock								124.3
Total assets		4,208.2		471.1		414.2		5,093.5
Construction and acquisition expenditures		245.6		21.2		26.9		293.7

	Electric		Gas		Other			Total
2010
Operating revenues	$	1,464.3	$	274.3	$	57.2		$	1,795.8
Depreciation and amortization		157.1		14.6		5.3			177.0
Operating income (loss)		239.7		23.6		(1.4	)		261.9
Interest expense, net of AFUDC									76.7
Interest income and other									(0.5	)
Income taxes									42.3
Net income									143.4
Preferred dividends									15.4
Earnings available for common stock									128.0
Total assets		4,025.3		460.3		452.0			4,937.6
Construction and acquisition expenditures		298.8		20.0		64.0			382.8

	Electric		Gas		Other			Total
2009
Operating revenues	$	1,315.6	$	308.8	$	83.6		$	1,708.0
Depreciation and amortization		130.3		13.6		8.9			152.8
Operating income (loss)		196.8		27.7		(2.8	)		221.7
Interest expense, net of AFUDC									42.5
Interest income and other									(0.8	)
Income taxes									27.0
Net income									153.0
Preferred dividends									15.4
Earnings available for common stock									137.6
Total assets		3,976.6		461.4		454.2			4,892.2
Construction and acquisition expenditures		711.3		17.5		4.8			733.6

WPL [Member]

Schedule Of Segments Of Business

	Electric			Gas		Other			Total
2011
Operating revenues	$	1,227.5		$	200.4	$	6.5		$	1,434.4
Depreciation and amortization		127.7			12.4		—			140.1
Operating income (loss)		262.6			27.2		(9.4	)		280.4
Interest expense, net of AFUDC										73.7
Equity income from unconsolidated investments		(38.7	)		—		—			(38.7	)
Income taxes										81.9
Net income										163.5
Preferred dividends										3.3
Earnings available for common stock										160.2
Total assets		3,316.3			360.8		366.9			4,044.0
Investments in equity method subsidiaries		246.5			—		—			246.5
Construction and acquisition expenditures		297.1			16.8		0.5			314.4

	Electric			Gas		Other			Total
2010
Operating revenues	$	1,209.9		$	206.3	$	7.4		$	1,423.6
Depreciation and amortization		98.0			10.6		—			108.6
Operating income (loss)		250.1			29.8		(1.1	)		278.8
Interest expense, net of AFUDC										66.1
Equity income from unconsolidated investments		(37.8	)		—		—			(37.8	)
Interest income and other										(0.1	)
Income taxes										98.3
Net income										152.3
Preferred dividends										3.3
Earnings available for common stock										149.0
Total assets		3,201.9			357.3		330.4			3,889.6
Investments in equity method subsidiaries		236.0			—		—			236.0
Construction and acquisition expenditures		430.3			19.9		0.3			450.5

	Electric			Gas		Other			Total
2009
Operating revenues	$	1,160.3		$	216.5	$	9.3		$	1,386.1
Depreciation and amortization		103.2			12.2		—			115.4
Operating income (loss)		145.4			24.6		(3.0	)		167.0
Interest expense, net of AFUDC										69.1
Equity income from unconsolidated investments		(37.0	)		—		—			(37.0	)
Interest income and other										(0.4	)
Income taxes										45.8
Net income										89.5
Preferred dividends										3.3
Earnings available for common stock										86.2
Total assets		2,891.0			341.7		448.7			3,681.4
Investments in equity method subsidiaries		227.1			—		—			227.1
Construction and acquisition expenditures		480.5			27.7		0.2			508.4