Selected Consolidated Quarterly Financial Data

12 Months Ended

Dec. 31, 2011

Selected Consolidated Quarterly Financial Data

(17) SELECTED CONSOLIDATED QUARTERLY FINANCIAL DATA (UNAUDITED)

Alliant Energy - All "per share" references refer to earnings per diluted share. Summation of the individual quarters may not equal annual totals due to rounding. Refer to Note 18 for additional information on discontinued operations.

	2011								2010
	March 31		June 30		Sep. 30		Dec. 31		March 31		June 30			Sep. 30			Dec. 31
	(in millions, except per share data)
Operating revenues	$	945.0	$	819.5	$	1,021.6	$	879.2	$	890.2	$	741.6		$	951.7		$	832.6
Operating income		127.8		72.0		185.1		93.5		109.0		100.7			246.6			99.8
Amounts attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax		72.2		51.1		122.0		57.0		43.4		48.0			150.9			47.0
Income (loss) from discontinued operations, net of tax (Refer to Note 18)		1.3		—		—		—		—		(0.2	)		(1.8	)		0.3
Net income		73.5		51.1		122.0		57.0		43.4		47.8			149.1			47.3
Earnings per weighted average common share attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax		0.65		0.46		1.10		0.51		0.39		0.43			1.37			0.43
Income (loss) from discontinued operations, net of tax		0.01		—		—		—		—		—			(0.02	)		—
Net income		0.66		0.46		1.10		0.51		0.39		0.43			1.35			0.43

IPL

	2011									2010
	March 31		June 30			Sep. 30		Dec. 31		March 31		June 30		Sep. 30		Dec. 31
	(in millions)
Operating revenues	$	477.5	$	374.1		$	484.5	$	404.0	$	454.5	$	389.3	$	534.8	$	417.2
Operating income		47.1		18.5			116.5		26.3		38.3		45.2		155.7		22.7
Net income		27.1		1.0			101.4		9.8		9.7		21.2		100.6		11.9
Earnings available (loss) for common stock		21.7		(2.3	)		98.3		6.6		5.8		17.4		96.8		8.0

Earnings per share data is not disclosed for IPL given Alliant Energy is the sole shareowner of all shares of IPL's common stock outstanding during the periods presented.

WPL

	2011								2010
	March 31		June 30		Sep. 30		Dec. 31		March 31		June 30		Sep. 30		Dec. 31
	(in millions)
Operating revenues	$	388.5	$	326.8	$	374.6	$	344.5	$	392.9	$	312.9	$	369.6	$	348.2
Operating income		74.8		45.5		86.9		73.2		69.7		52.3		86.7		70.1
Net income		44.4		25.0		51.4		42.7		37.0		30.2		50.0		35.1
Earnings available for common stock		43.6		24.1		50.6		41.9		36.2		29.3		49.2		34.3

Earnings per share data is not disclosed for WPL given Alliant Energy is the sole shareowner of all shares of WPL's common stock outstanding during the periods presented.

IPL [Member]

Selected Consolidated Quarterly Financial Data

(17) SELECTED CONSOLIDATED QUARTERLY FINANCIAL DATA (UNAUDITED)

Alliant Energy - All "per share" references refer to earnings per diluted share. Summation of the individual quarters may not equal annual totals due to rounding. Refer to Note 18 for additional information on discontinued operations.

	2011								2010
	March 31		June 30		Sep. 30		Dec. 31		March 31		June 30			Sep. 30			Dec. 31
	(in millions, except per share data)
Operating revenues	$	945.0	$	819.5	$	1,021.6	$	879.2	$	890.2	$	741.6		$	951.7		$	832.6
Operating income		127.8		72.0		185.1		93.5		109.0		100.7			246.6			99.8
Amounts attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax		72.2		51.1		122.0		57.0		43.4		48.0			150.9			47.0
Income (loss) from discontinued operations, net of tax (Refer to Note 18)		1.3		—		—		—		—		(0.2	)		(1.8	)		0.3
Net income		73.5		51.1		122.0		57.0		43.4		47.8			149.1			47.3
Earnings per weighted average common share attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax		0.65		0.46		1.10		0.51		0.39		0.43			1.37			0.43
Income (loss) from discontinued operations, net of tax		0.01		—		—		—		—		—			(0.02	)		—
Net income		0.66		0.46		1.10		0.51		0.39		0.43			1.35			0.43

IPL

	2011									2010
	March 31		June 30			Sep. 30		Dec. 31		March 31		June 30		Sep. 30		Dec. 31
	(in millions)
Operating revenues	$	477.5	$	374.1		$	484.5	$	404.0	$	454.5	$	389.3	$	534.8	$	417.2
Operating income		47.1		18.5			116.5		26.3		38.3		45.2		155.7		22.7
Net income		27.1		1.0			101.4		9.8		9.7		21.2		100.6		11.9
Earnings available (loss) for common stock		21.7		(2.3	)		98.3		6.6		5.8		17.4		96.8		8.0

Earnings per share data is not disclosed for IPL given Alliant Energy is the sole shareowner of all shares of IPL's common stock outstanding during the periods presented.

WPL

	2011								2010
	March 31		June 30		Sep. 30		Dec. 31		March 31		June 30		Sep. 30		Dec. 31
	(in millions)
Operating revenues	$	388.5	$	326.8	$	374.6	$	344.5	$	392.9	$	312.9	$	369.6	$	348.2
Operating income		74.8		45.5		86.9		73.2		69.7		52.3		86.7		70.1
Net income		44.4		25.0		51.4		42.7		37.0		30.2		50.0		35.1
Earnings available for common stock		43.6		24.1		50.6		41.9		36.2		29.3		49.2		34.3

Earnings per share data is not disclosed for WPL given Alliant Energy is the sole shareowner of all shares of WPL's common stock outstanding during the periods presented.

WPL [Member]

Selected Consolidated Quarterly Financial Data

(17) SELECTED CONSOLIDATED QUARTERLY FINANCIAL DATA (UNAUDITED)

Alliant Energy - All "per share" references refer to earnings per diluted share. Summation of the individual quarters may not equal annual totals due to rounding. Refer to Note 18 for additional information on discontinued operations.

	2011								2010
	March 31		June 30		Sep. 30		Dec. 31		March 31		June 30			Sep. 30			Dec. 31
	(in millions, except per share data)
Operating revenues	$	945.0	$	819.5	$	1,021.6	$	879.2	$	890.2	$	741.6		$	951.7		$	832.6
Operating income		127.8		72.0		185.1		93.5		109.0		100.7			246.6			99.8
Amounts attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax		72.2		51.1		122.0		57.0		43.4		48.0			150.9			47.0
Income (loss) from discontinued operations, net of tax (Refer to Note 18)		1.3		—		—		—		—		(0.2	)		(1.8	)		0.3
Net income		73.5		51.1		122.0		57.0		43.4		47.8			149.1			47.3
Earnings per weighted average common share attributable to Alliant Energy common shareowners:
Income from continuing operations, net of tax		0.65		0.46		1.10		0.51		0.39		0.43			1.37			0.43
Income (loss) from discontinued operations, net of tax		0.01		—		—		—		—		—			(0.02	)		—
Net income		0.66		0.46		1.10		0.51		0.39		0.43			1.35			0.43

IPL

	2011									2010
	March 31		June 30			Sep. 30		Dec. 31		March 31		June 30		Sep. 30		Dec. 31
	(in millions)
Operating revenues	$	477.5	$	374.1		$	484.5	$	404.0	$	454.5	$	389.3	$	534.8	$	417.2
Operating income		47.1		18.5			116.5		26.3		38.3		45.2		155.7		22.7
Net income		27.1		1.0			101.4		9.8		9.7		21.2		100.6		11.9
Earnings available (loss) for common stock		21.7		(2.3	)		98.3		6.6		5.8		17.4		96.8		8.0

Earnings per share data is not disclosed for IPL given Alliant Energy is the sole shareowner of all shares of IPL's common stock outstanding during the periods presented.

WPL

	2011								2010
	March 31		June 30		Sep. 30		Dec. 31		March 31		June 30		Sep. 30		Dec. 31
	(in millions)
Operating revenues	$	388.5	$	326.8	$	374.6	$	344.5	$	392.9	$	312.9	$	369.6	$	348.2
Operating income		74.8		45.5		86.9		73.2		69.7		52.3		86.7		70.1
Net income		44.4		25.0		51.4		42.7		37.0		30.2		50.0		35.1
Earnings available for common stock		43.6		24.1		50.6		41.9		36.2		29.3		49.2		34.3

Earnings per share data is not disclosed for WPL given Alliant Energy is the sole shareowner of all shares of WPL's common stock outstanding during the periods presented.