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Redeemable Preferred Stock | 12 Months Ended
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Dec. 31, 2017
Redeemable Preferred Stock | REDEEMABLE PREFERRED STOCK IPL is authorized to issue up to 16,000,000 shares of cumulative preferred stock in aggregate. Information related to the carrying value of IPL’s cumulative preferred stock at December 31 was as follows:
Series |  | Liquidation Preference/Stated Value |  | Shares Authorized |  | Shares Outstanding |  | 2017 |  | 2016
|  |  |  |  |  |  |  | (in millions)
5.1% |  | $25 |  | 8,000,000 |  | 8,000,000 |  |  | $200.0 |  |  |  | $200.0 |
On or after March 15, 2018, IPL may, at its option, redeem the 5.1% cumulative preferred stock for cash at a redemption price of $25 per share plus accrued and unpaid dividends up to the redemption date. The current articles of incorporation of IPL contain a provision that grants the holders of its cumulative preferred stock voting rights to elect two members of IPL’s Board of Directors if preferred dividends equal to six or more quarterly dividend requirements (whether or not consecutive) are in arrears. Such voting rights would not provide the holders of IPL’s preferred stock control of the decision on redemption of IPL’s preferred stock and could not force IPL to exercise its call option. Therefore, IPL’s cumulative preferred stock is presented in total equity on Alliant Energy’s and IPL’s balance sheets in a manner consistent with noncontrolling interests. Refer to Note 14 for information on the fair value of cumulative preferred stock.
IPL [Member] |
Redeemable Preferred Stock | REDEEMABLE PREFERRED STOCK IPL is authorized to issue up to 16,000,000 shares of cumulative preferred stock in aggregate. Information related to the carrying value of IPL’s cumulative preferred stock at December 31 was as follows:
Series |  | Liquidation Preference/Stated Value |  | Shares Authorized |  | Shares Outstanding |  | 2017 |  | 2016
|  |  |  |  |  |  |  | (in millions)
5.1% |  | $25 |  | 8,000,000 |  | 8,000,000 |  |  | $200.0 |  |  |  | $200.0 |
On or after March 15, 2018, IPL may, at its option, redeem the 5.1% cumulative preferred stock for cash at a redemption price of $25 per share plus accrued and unpaid dividends up to the redemption date. The current articles of incorporation of IPL contain a provision that grants the holders of its cumulative preferred stock voting rights to elect two members of IPL’s Board of Directors if preferred dividends equal to six or more quarterly dividend requirements (whether or not consecutive) are in arrears. Such voting rights would not provide the holders of IPL’s preferred stock control of the decision on redemption of IPL’s preferred stock and could not force IPL to exercise its call option. Therefore, IPL’s cumulative preferred stock is presented in total equity on Alliant Energy’s and IPL’s balance sheets in a manner consistent with noncontrolling interests. Refer to Note 14 for information on the fair value of cumulative preferred stock.

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- Definition The entire disclosure for terms, amounts, nature of changes, rights and privileges, dividends, and other matters related to preferred stock. + References No definition available. + Details
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