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Common Equity | 12 Months Ended
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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 |  |  | — |  |  | — |

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- Definition The entire disclosure for shareholders' equity, comprised of portions attributable to the parent entity and noncontrolling interest, if any, including other comprehensive income (as applicable). Including, but not limited to: (1) balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings; (2) accumulated balance for each classification of other comprehensive income and total amount of comprehensive income; (3) amount and nature of changes in separate accounts, including the number of shares authorized and outstanding, number of shares issued upon exercise and conversion, and for other comprehensive income, the adjustments for reclassifications to net income; (4) rights and privileges of each class of stock authorized; (5) basis of treasury stock, if other than cost, and amounts paid and accounting treatment for treasury stock purchased significantly in excess of market; (6) dividends paid or payable per share and in the aggregate for each class of stock for each period presented; (7) dividend restrictions and accumulated preferred dividends in arrears (in aggregate and per share amount); (8) retained earnings appropriations or restrictions, such as dividend restrictions; (9) impact of change in accounting principle, initial adoption of new accounting principle and correction of an error in previously issued financial statements; (10) shares held in trust for Employee Stock Ownership Plan (ESOP); (11) deferred compensation related to issuance of capital stock; (12) note received for issuance of stock; (13) unamortized discount on shares; (14) description, terms, and number of warrants or rights outstanding; (15) shares under subscription and subscription receivables, effective date of new retained earnings after quasi-reorganization and deficit eliminated by quasi-reorganization and, for a period of at least ten years after the effective date, the point in time from which the new retained dates; and (16) retroactive effective of subsequent change in capital structure. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21488-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Preferred Stock -URI http://asc.fasb.org/extlink&oid=6521494 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SAB TOPIC 4.C) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187143-122770 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21484-112644 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644 Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644 Reference 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656 Reference 12: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Section B -Paragraph 7, 11A -Chapter 1 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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