Common Equity

12 Months Ended

Dec. 31, 2012

Schedule of Common Equity [Line Items]

Common Equity

COMMON EQUITY

Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows:

	2012		2011		2010
Shares outstanding, January 1	111,018,821		110,893,901		110,656,498
Equity-based compensation plans (Note 6(b))	20,195		164,400		260,316
Other (a)	(51,616	)	(39,480	)	(22,913	)
Shares outstanding, December 31	110,987,400		111,018,821		110,893,901

(a) Includes shares transferred from employees to Alliant Energy to satisfy tax withholding requirements in connection with the vesting of certain restricted stock under the equity-based compensation plans.

At December 31, 2012, Alliant Energy had a total of 8.4 million shares available for issuance in the aggregate, pursuant to its OIP, Shareowner Direct Plan and 401(k) Savings Plan.

Shareowner Rights Agreement - Alliant Energy has established an amended and restated Shareowner Rights Agreement. The rights under this agreement will only become exercisable if a person or group has acquired, or announced an intention to acquire, 15% or more of Alliant Energy’s outstanding common stock. Each right will initially entitle registered shareowners to purchase from Alliant Energy one-half of one share of Alliant Energy’s common stock. The rights will be exercisable at an initial price of $110.00 per full share, subject to adjustment. If any shareowner acquires 15% or more of the outstanding common stock of Alliant Energy, each right (subject to limitations) will entitle its holder to purchase, at the right’s then current exercise price, a number of common shares of Alliant Energy or of the acquirer having a market value at the time of twice the right’s per full share exercise price. Alliant Energy’s Board of Directors is authorized to reduce the 15% ownership threshold to not less than 10%. The amended and restated Shareowner Rights Agreement expires in December 2018.

Dividend Restrictions - Alliant Energy does not have any significant common stock dividend restrictions. IPL and WPL each have common stock dividend restrictions based on the terms of their outstanding preferred stock and applicable regulatory limitations. At December 31, 2012, IPL and WPL were in compliance with all such dividend restrictions.

IPL and WPL are restricted from paying common stock dividends to their parent company, Alliant Energy, if for any past or current dividend period, dividends on their respective preferred stock have not been paid, or declared and set apart for payment. IPL and WPL have paid all dividends on their respective preferred stock through 2012.

IPL’s most significant regulatory limitation on distributions to its parent company requires IPL to obtain IUB approval for a reasonable utility capital structure if its actual 13-month average common equity ratio (calculated on a financial basis consistent with IPL’s rate cases) falls below 42% of total capitalization. As of December 31, 2012, IPL’s amount of retained earnings that were free of dividend restrictions was $387 million.

Currently, WPL’s most significant regulatory limitation on distributions to its parent company is included in an order issued by the PSCW in 2012 that prohibits WPL from paying annual common stock dividends in excess of $119 million in 2013 if WPL’s actual 13-month average common equity ratio (calculated on a financial basis consistent with WPL’s rate cases) falls below 51.03%. WPL’s dividends are also restricted to the extent that such dividend would reduce WPL’s common stock equity ratio to less than 25%. As of December 31, 2012, WPL’s amount of retained earnings that were free of dividend restrictions was $119 million for 2013.

Restricted Net Assets of Subsidiaries - IPL and WPL do not have regulatory authority to lend or advance any amounts to their parent company. As of December 31, the amount of net assets of IPL and WPL that were not available to be transferred to their parent company in the form of cash dividends without the consent of IPL’s and WPL’s regulatory authorities was as follows (in billions):

	2012		2011
IPL		$1.1		$1.0
WPL	1.5		1.3

Capital Transactions With Subsidiaries - IPL, WPL and Resources paid common stock dividends and repayments of capital to their parent company, Alliant Energy, as follows (in millions):

	IPL						WPL						Resources
	2012		2011		2010		2012		2011		2010		2012		2011		2010
Common stock dividends		$122.9		$73.4		$—		$112.0		$112.1		$109.5		$—		$—		$—
Repayments of capital	—		100.7		118.2		—		—		—		—		—		65.0
Total distributions from common equity		$122.9		$174.1		$118.2		$112.0		$112.1		$109.5		$—		$—		$65.0

IPL, WPL, Resources and Corporate Services received capital contributions from their parent company, Alliant Energy, as follows (in millions):

	2012		2011		2010
IPL		$110.0		$54.0		$50.0
WPL	90.0		25.0		75.0
Resources	—		65.0		—
Corporate Services	30.0		—		—

IPL [Member]

Schedule of Common Equity [Line Items]

Common Equity

COMMON EQUITY

Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows:

	2012		2011		2010
Shares outstanding, January 1	111,018,821		110,893,901		110,656,498
Equity-based compensation plans (Note 6(b))	20,195		164,400		260,316
Other (a)	(51,616	)	(39,480	)	(22,913	)
Shares outstanding, December 31	110,987,400		111,018,821		110,893,901

(a) Includes shares transferred from employees to Alliant Energy to satisfy tax withholding requirements in connection with the vesting of certain restricted stock under the equity-based compensation plans.

At December 31, 2012, Alliant Energy had a total of 8.4 million shares available for issuance in the aggregate, pursuant to its OIP, Shareowner Direct Plan and 401(k) Savings Plan.

Shareowner Rights Agreement - Alliant Energy has established an amended and restated Shareowner Rights Agreement. The rights under this agreement will only become exercisable if a person or group has acquired, or announced an intention to acquire, 15% or more of Alliant Energy’s outstanding common stock. Each right will initially entitle registered shareowners to purchase from Alliant Energy one-half of one share of Alliant Energy’s common stock. The rights will be exercisable at an initial price of $110.00 per full share, subject to adjustment. If any shareowner acquires 15% or more of the outstanding common stock of Alliant Energy, each right (subject to limitations) will entitle its holder to purchase, at the right’s then current exercise price, a number of common shares of Alliant Energy or of the acquirer having a market value at the time of twice the right’s per full share exercise price. Alliant Energy’s Board of Directors is authorized to reduce the 15% ownership threshold to not less than 10%. The amended and restated Shareowner Rights Agreement expires in December 2018.

Dividend Restrictions - Alliant Energy does not have any significant common stock dividend restrictions. IPL and WPL each have common stock dividend restrictions based on the terms of their outstanding preferred stock and applicable regulatory limitations. At December 31, 2012, IPL and WPL were in compliance with all such dividend restrictions.

IPL and WPL are restricted from paying common stock dividends to their parent company, Alliant Energy, if for any past or current dividend period, dividends on their respective preferred stock have not been paid, or declared and set apart for payment. IPL and WPL have paid all dividends on their respective preferred stock through 2012.

IPL’s most significant regulatory limitation on distributions to its parent company requires IPL to obtain IUB approval for a reasonable utility capital structure if its actual 13-month average common equity ratio (calculated on a financial basis consistent with IPL’s rate cases) falls below 42% of total capitalization. As of December 31, 2012, IPL’s amount of retained earnings that were free of dividend restrictions was $387 million.

Currently, WPL’s most significant regulatory limitation on distributions to its parent company is included in an order issued by the PSCW in 2012 that prohibits WPL from paying annual common stock dividends in excess of $119 million in 2013 if WPL’s actual 13-month average common equity ratio (calculated on a financial basis consistent with WPL’s rate cases) falls below 51.03%. WPL’s dividends are also restricted to the extent that such dividend would reduce WPL’s common stock equity ratio to less than 25%. As of December 31, 2012, WPL’s amount of retained earnings that were free of dividend restrictions was $119 million for 2013.

Restricted Net Assets of Subsidiaries - IPL and WPL do not have regulatory authority to lend or advance any amounts to their parent company. As of December 31, the amount of net assets of IPL and WPL that were not available to be transferred to their parent company in the form of cash dividends without the consent of IPL’s and WPL’s regulatory authorities was as follows (in billions):

	2012		2011
IPL		$1.1		$1.0
WPL	1.5		1.3

Capital Transactions With Subsidiaries - IPL, WPL and Resources paid common stock dividends and repayments of capital to their parent company, Alliant Energy, as follows (in millions):

	IPL						WPL						Resources
	2012		2011		2010		2012		2011		2010		2012		2011		2010
Common stock dividends		$122.9		$73.4		$—		$112.0		$112.1		$109.5		$—		$—		$—
Repayments of capital	—		100.7		118.2		—		—		—		—		—		65.0
Total distributions from common equity		$122.9		$174.1		$118.2		$112.0		$112.1		$109.5		$—		$—		$65.0

IPL, WPL, Resources and Corporate Services received capital contributions from their parent company, Alliant Energy, as follows (in millions):

	2012		2011		2010
IPL		$110.0		$54.0		$50.0
WPL	90.0		25.0		75.0
Resources	—		65.0		—
Corporate Services	30.0		—		—

WPL [Member]

Schedule of Common Equity [Line Items]

Common Equity

COMMON EQUITY

Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows:

	2012		2011		2010
Shares outstanding, January 1	111,018,821		110,893,901		110,656,498
Equity-based compensation plans (Note 6(b))	20,195		164,400		260,316
Other (a)	(51,616	)	(39,480	)	(22,913	)
Shares outstanding, December 31	110,987,400		111,018,821		110,893,901

(a) Includes shares transferred from employees to Alliant Energy to satisfy tax withholding requirements in connection with the vesting of certain restricted stock under the equity-based compensation plans.

At December 31, 2012, Alliant Energy had a total of 8.4 million shares available for issuance in the aggregate, pursuant to its OIP, Shareowner Direct Plan and 401(k) Savings Plan.

Shareowner Rights Agreement - Alliant Energy has established an amended and restated Shareowner Rights Agreement. The rights under this agreement will only become exercisable if a person or group has acquired, or announced an intention to acquire, 15% or more of Alliant Energy’s outstanding common stock. Each right will initially entitle registered shareowners to purchase from Alliant Energy one-half of one share of Alliant Energy’s common stock. The rights will be exercisable at an initial price of $110.00 per full share, subject to adjustment. If any shareowner acquires 15% or more of the outstanding common stock of Alliant Energy, each right (subject to limitations) will entitle its holder to purchase, at the right’s then current exercise price, a number of common shares of Alliant Energy or of the acquirer having a market value at the time of twice the right’s per full share exercise price. Alliant Energy’s Board of Directors is authorized to reduce the 15% ownership threshold to not less than 10%. The amended and restated Shareowner Rights Agreement expires in December 2018.

Dividend Restrictions - Alliant Energy does not have any significant common stock dividend restrictions. IPL and WPL each have common stock dividend restrictions based on the terms of their outstanding preferred stock and applicable regulatory limitations. At December 31, 2012, IPL and WPL were in compliance with all such dividend restrictions.

IPL and WPL are restricted from paying common stock dividends to their parent company, Alliant Energy, if for any past or current dividend period, dividends on their respective preferred stock have not been paid, or declared and set apart for payment. IPL and WPL have paid all dividends on their respective preferred stock through 2012.

IPL’s most significant regulatory limitation on distributions to its parent company requires IPL to obtain IUB approval for a reasonable utility capital structure if its actual 13-month average common equity ratio (calculated on a financial basis consistent with IPL’s rate cases) falls below 42% of total capitalization. As of December 31, 2012, IPL’s amount of retained earnings that were free of dividend restrictions was $387 million.

Currently, WPL’s most significant regulatory limitation on distributions to its parent company is included in an order issued by the PSCW in 2012 that prohibits WPL from paying annual common stock dividends in excess of $119 million in 2013 if WPL’s actual 13-month average common equity ratio (calculated on a financial basis consistent with WPL’s rate cases) falls below 51.03%. WPL’s dividends are also restricted to the extent that such dividend would reduce WPL’s common stock equity ratio to less than 25%. As of December 31, 2012, WPL’s amount of retained earnings that were free of dividend restrictions was $119 million for 2013.

Restricted Net Assets of Subsidiaries - IPL and WPL do not have regulatory authority to lend or advance any amounts to their parent company. As of December 31, the amount of net assets of IPL and WPL that were not available to be transferred to their parent company in the form of cash dividends without the consent of IPL’s and WPL’s regulatory authorities was as follows (in billions):

	2012		2011
IPL		$1.1		$1.0
WPL	1.5		1.3

Capital Transactions With Subsidiaries - IPL, WPL and Resources paid common stock dividends and repayments of capital to their parent company, Alliant Energy, as follows (in millions):

	IPL						WPL						Resources
	2012		2011		2010		2012		2011		2010		2012		2011		2010
Common stock dividends		$122.9		$73.4		$—		$112.0		$112.1		$109.5		$—		$—		$—
Repayments of capital	—		100.7		118.2		—		—		—		—		—		65.0
Total distributions from common equity		$122.9		$174.1		$118.2		$112.0		$112.1		$109.5		$—		$—		$65.0

IPL, WPL, Resources and Corporate Services received capital contributions from their parent company, Alliant Energy, as follows (in millions):

	2012		2011		2010
IPL		$110.0		$54.0		$50.0
WPL	90.0		25.0		75.0
Resources	—		65.0		—
Corporate Services	30.0		—		—