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Common Equity (Tables) | 3 Months Ended
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Mar. 31, 2022
Schedule of Capitalization, Equity [Line Items] |
Common Share Activity | A summary of Alliant Energy’s common stock activity was as follows:
Shares outstanding, January 1, 2022 | 250,474,529 |
Shareowner Direct Plan | 116,431 |
Equity-based compensation plans | 222,768 |
Shares outstanding, March 31, 2022 | 250,813,728 |
Changes in Shareowners' Equity | A summary of changes in shareowners’ equity was as follows (in millions):
Alliant Energy | Total Alliant Energy Common Equity |  |  |  |
|  |  |  |  |  |  | Accumulated |  | Shares in |  | Cumulative |  |
|  |  | Additional |  |  |  | Other |  | Deferred |  | Preferred |  |
| Common |  | Paid-In |  | Retained |  | Comprehensive |  | Compensation |  | Stock |  | Total
| Stock |  | Capital |  | Earnings |  | Loss |  | Trust |  | of IPL |  | Equity
Three Months Ended March 31, 2022 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $3 |  | $2,749 |  | $3,250 |  | $— |  | ($12) |  | $— |  | $5,990
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 192 |  |  |  |  |  |  |  | 192
Common stock dividends ($0.4275 per share) |  |  |  |  | (107) |  |  |  |  |  |  |  | (107)
Shareowner Direct Plan issuances |  |  | 7 |  |  |  |  |  |  |  |  |  | 7
Equity-based compensation plans and other |  |  | (6) |  | 1 |  |  |  |  |  |  |  | (5)
Ending balance, March 31, 2022 | $3 |  | $2,750 |  | $3,336 |  | $— |  | ($12) |  | $— |  | $6,077
Three Months Ended March 31, 2021 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $2 |  | $2,704 |  | $2,994 |  | ($1) |  | ($11) |  | $200 |  | $5,888
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 171 |  |  |  |  |  |  |  | 171
Common stock dividends ($0.4025 per share) |  |  |  |  | (102) |  |  |  |  |  |  |  | (102)
Shareowner Direct Plan issuances | 1 |  | 7 |  |  |  |  |  |  |  |  |  | 8
Equity-based compensation plans and other |  |  | 1 |  |  |  |  |  |  |  |  |  | 1
Ending balance, March 31, 2021 | $3 |  | $2,712 |  | $3,063 |  | ($1) |  | ($11) |  | $200 |  | $5,966
IPL | Total IPL Common Equity |  |  |  |
|  |  | Additional |  |  |  | Cumulative |  |
| Common |  | Paid-In |  | Retained |  | Preferred |  | Total
| Stock |  | Capital |  | Earnings |  | Stock |  | Equity
Three Months Ended March 31, 2022 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $33 |  | $2,807 |  | $929 |  | $— |  | $3,769
Net income available for common stock |  |  |  |  | 87 |  |  |  | 87
Common stock dividends |  |  |  |  | (81) |  |  |  | (81)
Ending balance, March 31, 2022 | $33 |  | $2,807 |  | $935 |  | $— |  | $3,775
Three Months Ended March 31, 2021 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $33 |  | $2,752 |  | $979 |  | $200 |  | $3,964
Net income available for common stock |  |  |  |  | 79 |  |  |  | 79
Common stock dividends |  |  |  |  | (101) |  |  |  | (101)
Ending balance, March 31, 2021 | $33 |  | $2,752 |  | $957 |  | $200 |  | $3,942
WPL |  |  | Additional |  |  |  | Total
| Common |  | Paid-In |  | Retained |  | Common
| Stock |  | Capital |  | Earnings |  | Equity
Three Months Ended March 31, 2022 |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $66 |  | $1,704 |  | $1,053 |  | $2,823
Net income |  |  |  |  | 92 |  | 92
Common stock dividends |  |  |  |  | (44) |  | (44)
Capital contributions from parent |  |  | 180 |  |  |  | 180
Ending balance, March 31, 2022 | $66 |  | $1,884 |  | $1,101 |  | $3,051
Three Months Ended March 31, 2021 |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $66 |  | $1,459 |  | $953 |  | $2,478
Net income |  |  |  |  | 84 |  | 84
Common stock dividends |  |  |  |  | (42) |  | (42)
Capital contributions from parent |  |  | 125 |  |  |  | 125
Ending balance, March 31, 2021 | $66 |  | $1,584 |  | $995 |  | $2,645
IPL [Member] |
Schedule of Capitalization, Equity [Line Items] |
Changes in Shareowners' Equity | A summary of changes in shareowners’ equity was as follows (in millions):
Alliant Energy | Total Alliant Energy Common Equity |  |  |  |
|  |  |  |  |  |  | Accumulated |  | Shares in |  | Cumulative |  |
|  |  | Additional |  |  |  | Other |  | Deferred |  | Preferred |  |
| Common |  | Paid-In |  | Retained |  | Comprehensive |  | Compensation |  | Stock |  | Total
| Stock |  | Capital |  | Earnings |  | Loss |  | Trust |  | of IPL |  | Equity
Three Months Ended March 31, 2022 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $3 |  | $2,749 |  | $3,250 |  | $— |  | ($12) |  | $— |  | $5,990
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 192 |  |  |  |  |  |  |  | 192
Common stock dividends ($0.4275 per share) |  |  |  |  | (107) |  |  |  |  |  |  |  | (107)
Shareowner Direct Plan issuances |  |  | 7 |  |  |  |  |  |  |  |  |  | 7
Equity-based compensation plans and other |  |  | (6) |  | 1 |  |  |  |  |  |  |  | (5)
Ending balance, March 31, 2022 | $3 |  | $2,750 |  | $3,336 |  | $— |  | ($12) |  | $— |  | $6,077
Three Months Ended March 31, 2021 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $2 |  | $2,704 |  | $2,994 |  | ($1) |  | ($11) |  | $200 |  | $5,888
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 171 |  |  |  |  |  |  |  | 171
Common stock dividends ($0.4025 per share) |  |  |  |  | (102) |  |  |  |  |  |  |  | (102)
Shareowner Direct Plan issuances | 1 |  | 7 |  |  |  |  |  |  |  |  |  | 8
Equity-based compensation plans and other |  |  | 1 |  |  |  |  |  |  |  |  |  | 1
Ending balance, March 31, 2021 | $3 |  | $2,712 |  | $3,063 |  | ($1) |  | ($11) |  | $200 |  | $5,966
IPL | Total IPL Common Equity |  |  |  |
|  |  | Additional |  |  |  | Cumulative |  |
| Common |  | Paid-In |  | Retained |  | Preferred |  | Total
| Stock |  | Capital |  | Earnings |  | Stock |  | Equity
Three Months Ended March 31, 2022 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $33 |  | $2,807 |  | $929 |  | $— |  | $3,769
Net income available for common stock |  |  |  |  | 87 |  |  |  | 87
Common stock dividends |  |  |  |  | (81) |  |  |  | (81)
Ending balance, March 31, 2022 | $33 |  | $2,807 |  | $935 |  | $— |  | $3,775
Three Months Ended March 31, 2021 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $33 |  | $2,752 |  | $979 |  | $200 |  | $3,964
Net income available for common stock |  |  |  |  | 79 |  |  |  | 79
Common stock dividends |  |  |  |  | (101) |  |  |  | (101)
Ending balance, March 31, 2021 | $33 |  | $2,752 |  | $957 |  | $200 |  | $3,942
WPL |  |  | Additional |  |  |  | Total
| Common |  | Paid-In |  | Retained |  | Common
| Stock |  | Capital |  | Earnings |  | Equity
Three Months Ended March 31, 2022 |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $66 |  | $1,704 |  | $1,053 |  | $2,823
Net income |  |  |  |  | 92 |  | 92
Common stock dividends |  |  |  |  | (44) |  | (44)
Capital contributions from parent |  |  | 180 |  |  |  | 180
Ending balance, March 31, 2022 | $66 |  | $1,884 |  | $1,101 |  | $3,051
Three Months Ended March 31, 2021 |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $66 |  | $1,459 |  | $953 |  | $2,478
Net income |  |  |  |  | 84 |  | 84
Common stock dividends |  |  |  |  | (42) |  | (42)
Capital contributions from parent |  |  | 125 |  |  |  | 125
Ending balance, March 31, 2021 | $66 |  | $1,584 |  | $995 |  | $2,645
WPL [Member] |
Schedule of Capitalization, Equity [Line Items] |
Changes in Shareowners' Equity | A summary of changes in shareowners’ equity was as follows (in millions):
Alliant Energy | Total Alliant Energy Common Equity |  |  |  |
|  |  |  |  |  |  | Accumulated |  | Shares in |  | Cumulative |  |
|  |  | Additional |  |  |  | Other |  | Deferred |  | Preferred |  |
| Common |  | Paid-In |  | Retained |  | Comprehensive |  | Compensation |  | Stock |  | Total
| Stock |  | Capital |  | Earnings |  | Loss |  | Trust |  | of IPL |  | Equity
Three Months Ended March 31, 2022 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $3 |  | $2,749 |  | $3,250 |  | $— |  | ($12) |  | $— |  | $5,990
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 192 |  |  |  |  |  |  |  | 192
Common stock dividends ($0.4275 per share) |  |  |  |  | (107) |  |  |  |  |  |  |  | (107)
Shareowner Direct Plan issuances |  |  | 7 |  |  |  |  |  |  |  |  |  | 7
Equity-based compensation plans and other |  |  | (6) |  | 1 |  |  |  |  |  |  |  | (5)
Ending balance, March 31, 2022 | $3 |  | $2,750 |  | $3,336 |  | $— |  | ($12) |  | $— |  | $6,077
Three Months Ended March 31, 2021 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $2 |  | $2,704 |  | $2,994 |  | ($1) |  | ($11) |  | $200 |  | $5,888
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 171 |  |  |  |  |  |  |  | 171
Common stock dividends ($0.4025 per share) |  |  |  |  | (102) |  |  |  |  |  |  |  | (102)
Shareowner Direct Plan issuances | 1 |  | 7 |  |  |  |  |  |  |  |  |  | 8
Equity-based compensation plans and other |  |  | 1 |  |  |  |  |  |  |  |  |  | 1
Ending balance, March 31, 2021 | $3 |  | $2,712 |  | $3,063 |  | ($1) |  | ($11) |  | $200 |  | $5,966
IPL | Total IPL Common Equity |  |  |  |
|  |  | Additional |  |  |  | Cumulative |  |
| Common |  | Paid-In |  | Retained |  | Preferred |  | Total
| Stock |  | Capital |  | Earnings |  | Stock |  | Equity
Three Months Ended March 31, 2022 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $33 |  | $2,807 |  | $929 |  | $— |  | $3,769
Net income available for common stock |  |  |  |  | 87 |  |  |  | 87
Common stock dividends |  |  |  |  | (81) |  |  |  | (81)
Ending balance, March 31, 2022 | $33 |  | $2,807 |  | $935 |  | $— |  | $3,775
Three Months Ended March 31, 2021 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $33 |  | $2,752 |  | $979 |  | $200 |  | $3,964
Net income available for common stock |  |  |  |  | 79 |  |  |  | 79
Common stock dividends |  |  |  |  | (101) |  |  |  | (101)
Ending balance, March 31, 2021 | $33 |  | $2,752 |  | $957 |  | $200 |  | $3,942
WPL |  |  | Additional |  |  |  | Total
| Common |  | Paid-In |  | Retained |  | Common
| Stock |  | Capital |  | Earnings |  | Equity
Three Months Ended March 31, 2022 |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $66 |  | $1,704 |  | $1,053 |  | $2,823
Net income |  |  |  |  | 92 |  | 92
Common stock dividends |  |  |  |  | (44) |  | (44)
Capital contributions from parent |  |  | 180 |  |  |  | 180
Ending balance, March 31, 2022 | $66 |  | $1,884 |  | $1,101 |  | $3,051
Three Months Ended March 31, 2021 |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $66 |  | $1,459 |  | $953 |  | $2,478
Net income |  |  |  |  | 84 |  | 84
Common stock dividends |  |  |  |  | (42) |  | (42)
Capital contributions from parent |  |  | 125 |  |  |  | 125
Ending balance, March 31, 2021 | $66 |  | $1,584 |  | $995 |  | $2,645

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