XML 33 R10.htm IDEA: XBRL DOCUMENT
v3.20.2

Common Equity | 6 Months Ended
--- | ---
Jun. 30, 2020
Common Equity [Line Items] |
Common Equity | COMMON EQUITY Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows:
Shares outstanding, January 1, 2020 | 245,022,800 |
Equity forward agreements | 4,275,127 |
Shareowner Direct Plan | 248,220 |
Equity-based compensation plans | 98,205 |
Shares outstanding, June 30, 2020 | 249,644,352 |
Equity Forward Agreements - In November 2019, Alliant Energy entered into forward sale agreements with a counterparty in connection with a public offering of 4,275,127 shares of Alliant Energy common stock. The initial forward sale price of $52.235 per share was subject to daily adjustment based on a floating interest rate factor, and decreased by other fixed amounts specified in the forward sale agreements. In the first quarter of 2020, Alliant Energy settled $222 million under the forward sale agreements by delivering 4,275,127 shares of newly issued Alliant Energy common stock at a weighted average forward sale price of $51.98 per share. Alliant Energy used the net proceeds from the settlements for general corporate purposes. 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 |  | Income (Loss) |  | Trust |  | of IPL |  | Equity
Three Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2020 |  | $2.5 |  |  |  | $2,674.1 |  |  |  | $2,833.7 |  |  |  | $2.0 |  |  |  | ($9.9 | ) |  |  | $200.0 |  |  |  | $5,702.4 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 134.4 |  |  |  |  |  |  |  |  | 134.4 |
Common stock dividends ($0.38 per share) |  |  |  |  | (94.6 | ) |  |  |  |  |  |  |  | (94.6 | )
Shareowner Direct Plan issuances |  |  |  | 6.4 |  |  |  |  |  |  |  |  |  |  | 6.4 |
Equity-based compensation plans and other |  |  | 2.6 |  |  |  |  |  |  | (0.3 | ) |  |  |  | 2.3 |
Other comprehensive loss, net of tax |  |  |  |  |  |  | (2.6 | ) |  |  |  |  |  | (2.6 | )
Ending balance, June 30, 2020 |  | $2.5 |  |  |  | $2,683.1 |  |  |  | $2,873.5 |  |  |  | ($0.6 | ) |  |  | ($10.2 | ) |  |  | $200.0 |  |  |  | $5,748.3 |
Three Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2019 |  | $2.4 |  |  |  | $2,100.0 |  |  |  | $2,587.3 |  |  |  | $2.4 |  |  |  | ($9.7 | ) |  |  | $200.0 |  |  |  | $4,882.4 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 94.6 |  |  |  |  |  |  |  |  | 94.6 |
Common stock dividends ($0.355 per share) |  |  |  |  | (84.1 | ) |  |  |  |  |  |  |  | (84.1 | )
Shareowner Direct Plan issuances |  |  |  | 6.0 |  |  |  |  |  |  |  |  |  |  | 6.0 |
Equity-based compensation plans and other |  |  | 2.4 |  |  |  |  |  |  | (0.3 | ) |  |  |  | 2.1 |
Other comprehensive loss, net of tax |  |  |  |  |  |  | (1.4 | ) |  |  |  |  |  | (1.4 | )
Ending balance, June 30, 2019 |  | $2.4 |  |  |  | $2,108.4 |  |  |  | $2,597.8 |  |  |  | $1.0 |  |  |  | ($10.0 | ) |  |  | $200.0 |  |  |  | $4,899.6 |
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 |  | Income (Loss) |  | Trust |  | of IPL |  | Equity
Six Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2019 |  | $2.5 |  |  |  | $2,445.9 |  |  |  | $2,765.4 |  |  |  | $1.3 |  |  |  | ($10.0 | ) |  |  | $200.0 |  |  |  | $5,405.1 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 304.4 |  |  |  |  |  |  |  |  | 304.4 |
Common stock dividends ($0.76 per share) |  |  |  |  | (187.6 | ) |  |  |  |  |  |  |  | (187.6 | )
Equity forward settlements and Shareowner Direct Plan issuances |  |  |  | 234.8 |  |  |  |  |  |  |  |  |  |  | 234.8 |
Equity-based compensation plans and other |  |  | 2.4 |  |  |  |  |  |  | (0.2 | ) |  |  |  | 2.2 |
Adoption of new accounting standard, net of tax (refer to Note 1(d)) |  |  |  |  | (8.7 | ) |  |  |  |  |  |  |  | (8.7 | )
Other comprehensive loss, net of tax |  |  |  |  |  |  | (1.9 | ) |  |  |  |  |  | (1.9 | )
Ending balance, June 30, 2020 |  | $2.5 |  |  |  | $2,683.1 |  |  |  | $2,873.5 |  |  |  | ($0.6 | ) |  |  | ($10.2 | ) |  |  | $200.0 |  |  |  | $5,748.3 |
Six Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2018 |  | $2.4 |  |  |  | $2,045.5 |  |  |  | $2,545.9 |  |  |  | $1.7 |  |  |  | ($9.8 | ) |  |  | $200.0 |  |  |  | $4,785.7 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 219.7 |  |  |  |  |  |  |  |  | 219.7 |
Common stock dividends ($0.71 per share) |  |  |  |  | (167.8 | ) |  |  |  |  |  |  |  | (167.8 | )
Equity forward settlements and Shareowner Direct Plan issuances |  |  | 60.6 |  |  |  |  |  |  |  |  |  |  | 60.6 |
Equity-based compensation plans and other |  |  | 2.3 |  |  |  |  |  |  | (0.2 | ) |  |  |  | 2.1 |
Other comprehensive loss, net of tax |  |  |  |  |  |  | (0.7 | ) |  |  |  |  |  | (0.7 | )
Ending balance, June 30, 2019 |  | $2.4 |  |  |  | $2,108.4 |  |  |  | $2,597.8 |  |  |  | $1.0 |  |  |  | ($10.0 | ) |  |  | $200.0 |  |  |  | $4,899.6 |
IPL | Total IPL Common Equity |  |  |  |
|  |  | Additional |  |  |  | Cumulative |  |
| Common |  | Paid-In |  | Retained |  | Preferred |  | Total
| Stock |  | Capital |  | Earnings |  | Stock |  | Equity
Three Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2020 |  | $33.4 |  |  |  | $2,447.8 |  |  |  | $914.2 |  |  |  | $200.0 |  |  |  | $3,595.4 |
Net income available for common stock |  |  |  |  | 59.8 |  |  |  |  | 59.8 |
Common stock dividends |  |  |  |  | (59.1 | ) |  |  |  | (59.1 | )
Capital contributions from parent |  |  | 75.0 |  |  |  |  |  |  | 75.0 |
Ending balance, June 30, 2020 |  | $33.4 |  |  |  | $2,522.8 |  |  |  | $914.9 |  |  |  | $200.0 |  |  |  | $3,671.1 |
Three Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2019 |  | $33.4 |  |  |  | $2,322.8 |  |  |  | $785.8 |  |  |  | $200.0 |  |  |  | $3,342.0 |
Net income available for common stock |  |  |  |  | 45.0 |  |  |  |  | 45.0 |
Common stock dividends |  |  |  |  | (41.9 | ) |  |  |  | (41.9 | )
Ending balance, June 30, 2019 |  | $33.4 |  |  |  | $2,322.8 |  |  |  | $788.9 |  |  |  | $200.0 |  |  |  | $3,345.1 |
IPL | Total IPL Common Equity |  |  |  |
|  |  | Additional |  |  |  | Cumulative |  |
| Common |  | Paid-In |  | Retained |  | Preferred |  | Total
| Stock |  | Capital |  | Earnings |  | Stock |  | Equity
Six Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2019 |  | $33.4 |  |  |  | $2,347.8 |  |  |  | $890.6 |  |  |  | $200.0 |  |  |  | $3,471.8 |
Net income available for common stock |  |  |  |  | 142.4 |  |  |  |  | 142.4 |
Common stock dividends |  |  |  |  | (118.1 | ) |  |  |  | (118.1 | )
Capital contributions from parent |  |  | 175.0 |  |  |  |  |  |  | 175.0 |
Ending balance, June 30, 2020 |  | $33.4 |  |  |  | $2,522.8 |  |  |  | $914.9 |  |  |  | $200.0 |  |  |  | $3,671.1 |
Six Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2018 |  | $33.4 |  |  |  | $2,222.8 |  |  |  | $774.5 |  |  |  | $200.0 |  |  |  | $3,230.7 |
Net income available for common stock |  |  |  |  | 98.3 |  |  |  |  | 98.3 |
Common stock dividends |  |  |  |  | (83.9 | ) |  |  |  | (83.9 | )
Capital contributions from parent |  |  | 100.0 |  |  |  |  |  |  | 100.0 |
Ending balance, June 30, 2019 |  | $33.4 |  |  |  | $2,322.8 |  |  |  | $788.9 |  |  |  | $200.0 |  |  |  | $3,345.1 |
WPL |  |  | Additional |  |  |  | Total
| Common |  | Paid-In |  | Retained |  | Common
| Stock |  | Capital |  | Earnings |  | Equity
Three Months Ended June 30, 2020 |  |  |  |  |  |  |
Beginning balance, March 31, 2020 |  | $66.2 |  |  |  | $1,459.0 |  |  |  | $910.9 |  |  |  | $2,436.1 |
Net income |  |  |  |  | 57.6 |  |  | 57.6 |
Common stock dividends |  |  |  |  | (41.9 | ) |  | (41.9 | )
Ending balance, June 30, 2020 |  | $66.2 |  |  |  | $1,459.0 |  |  |  | $926.6 |  |  |  | $2,451.8 |
Three Months Ended June 30, 2019 |  |  |  |  |  |  |
Beginning balance, March 31, 2019 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $804.0 |  |  |  | $2,179.2 |
Net income |  |  |  |  | 42.0 |  |  | 42.0 |
Common stock dividends |  |  |  |  | (36.0 | ) |  | (36.0 | )
Ending balance, June 30, 2019 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $810.0 |  |  |  | $2,185.2 |
WPL |  |  | Additional |  |  |  | Total
| Common |  | Paid-In |  | Retained |  | Common
| Stock |  | Capital |  | Earnings |  | Equity
Six Months Ended June 30, 2020 |  |  |  |  |  |  |
Beginning balance, December 31, 2019 |  | $66.2 |  |  |  | $1,434.0 |  |  |  | $863.4 |  |  |  | $2,363.6 |
Net income |  |  |  |  | 147.2 |  |  | 147.2 |
Common stock dividends |  |  |  |  | (84.0 | ) |  | (84.0 | )
Capital contributions from parent |  |  | 25.0 |  |  |  |  | 25.0 |
Ending balance, June 30, 2020 |  | $66.2 |  |  |  | $1,459.0 |  |  |  | $926.6 |  |  |  | $2,451.8 |
Six Months Ended June 30, 2019 |  |  |  |  |  |  |
Beginning balance, December 31, 2018 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $774.3 |  |  |  | $2,149.5 |
Net income |  |  |  |  | 107.7 |  |  | 107.7 |
Common stock dividends |  |  |  |  | (72.0 | ) |  | (72.0 | )
Ending balance, June 30, 2019 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $810.0 |  |  |  | $2,185.2 |
IPL [Member] |
Common Equity [Line Items] |
Common Equity | COMMON EQUITY Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows:
Shares outstanding, January 1, 2020 | 245,022,800 |
Equity forward agreements | 4,275,127 |
Shareowner Direct Plan | 248,220 |
Equity-based compensation plans | 98,205 |
Shares outstanding, June 30, 2020 | 249,644,352 |
Equity Forward Agreements - In November 2019, Alliant Energy entered into forward sale agreements with a counterparty in connection with a public offering of 4,275,127 shares of Alliant Energy common stock. The initial forward sale price of $52.235 per share was subject to daily adjustment based on a floating interest rate factor, and decreased by other fixed amounts specified in the forward sale agreements. In the first quarter of 2020, Alliant Energy settled $222 million under the forward sale agreements by delivering 4,275,127 shares of newly issued Alliant Energy common stock at a weighted average forward sale price of $51.98 per share. Alliant Energy used the net proceeds from the settlements for general corporate purposes. 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 |  | Income (Loss) |  | Trust |  | of IPL |  | Equity
Three Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2020 |  | $2.5 |  |  |  | $2,674.1 |  |  |  | $2,833.7 |  |  |  | $2.0 |  |  |  | ($9.9 | ) |  |  | $200.0 |  |  |  | $5,702.4 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 134.4 |  |  |  |  |  |  |  |  | 134.4 |
Common stock dividends ($0.38 per share) |  |  |  |  | (94.6 | ) |  |  |  |  |  |  |  | (94.6 | )
Shareowner Direct Plan issuances |  |  |  | 6.4 |  |  |  |  |  |  |  |  |  |  | 6.4 |
Equity-based compensation plans and other |  |  | 2.6 |  |  |  |  |  |  | (0.3 | ) |  |  |  | 2.3 |
Other comprehensive loss, net of tax |  |  |  |  |  |  | (2.6 | ) |  |  |  |  |  | (2.6 | )
Ending balance, June 30, 2020 |  | $2.5 |  |  |  | $2,683.1 |  |  |  | $2,873.5 |  |  |  | ($0.6 | ) |  |  | ($10.2 | ) |  |  | $200.0 |  |  |  | $5,748.3 |
Three Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2019 |  | $2.4 |  |  |  | $2,100.0 |  |  |  | $2,587.3 |  |  |  | $2.4 |  |  |  | ($9.7 | ) |  |  | $200.0 |  |  |  | $4,882.4 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 94.6 |  |  |  |  |  |  |  |  | 94.6 |
Common stock dividends ($0.355 per share) |  |  |  |  | (84.1 | ) |  |  |  |  |  |  |  | (84.1 | )
Shareowner Direct Plan issuances |  |  |  | 6.0 |  |  |  |  |  |  |  |  |  |  | 6.0 |
Equity-based compensation plans and other |  |  | 2.4 |  |  |  |  |  |  | (0.3 | ) |  |  |  | 2.1 |
Other comprehensive loss, net of tax |  |  |  |  |  |  | (1.4 | ) |  |  |  |  |  | (1.4 | )
Ending balance, June 30, 2019 |  | $2.4 |  |  |  | $2,108.4 |  |  |  | $2,597.8 |  |  |  | $1.0 |  |  |  | ($10.0 | ) |  |  | $200.0 |  |  |  | $4,899.6 |
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 |  | Income (Loss) |  | Trust |  | of IPL |  | Equity
Six Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2019 |  | $2.5 |  |  |  | $2,445.9 |  |  |  | $2,765.4 |  |  |  | $1.3 |  |  |  | ($10.0 | ) |  |  | $200.0 |  |  |  | $5,405.1 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 304.4 |  |  |  |  |  |  |  |  | 304.4 |
Common stock dividends ($0.76 per share) |  |  |  |  | (187.6 | ) |  |  |  |  |  |  |  | (187.6 | )
Equity forward settlements and Shareowner Direct Plan issuances |  |  |  | 234.8 |  |  |  |  |  |  |  |  |  |  | 234.8 |
Equity-based compensation plans and other |  |  | 2.4 |  |  |  |  |  |  | (0.2 | ) |  |  |  | 2.2 |
Adoption of new accounting standard, net of tax (refer to Note 1(d)) |  |  |  |  | (8.7 | ) |  |  |  |  |  |  |  | (8.7 | )
Other comprehensive loss, net of tax |  |  |  |  |  |  | (1.9 | ) |  |  |  |  |  | (1.9 | )
Ending balance, June 30, 2020 |  | $2.5 |  |  |  | $2,683.1 |  |  |  | $2,873.5 |  |  |  | ($0.6 | ) |  |  | ($10.2 | ) |  |  | $200.0 |  |  |  | $5,748.3 |
Six Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2018 |  | $2.4 |  |  |  | $2,045.5 |  |  |  | $2,545.9 |  |  |  | $1.7 |  |  |  | ($9.8 | ) |  |  | $200.0 |  |  |  | $4,785.7 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 219.7 |  |  |  |  |  |  |  |  | 219.7 |
Common stock dividends ($0.71 per share) |  |  |  |  | (167.8 | ) |  |  |  |  |  |  |  | (167.8 | )
Equity forward settlements and Shareowner Direct Plan issuances |  |  | 60.6 |  |  |  |  |  |  |  |  |  |  | 60.6 |
Equity-based compensation plans and other |  |  | 2.3 |  |  |  |  |  |  | (0.2 | ) |  |  |  | 2.1 |
Other comprehensive loss, net of tax |  |  |  |  |  |  | (0.7 | ) |  |  |  |  |  | (0.7 | )
Ending balance, June 30, 2019 |  | $2.4 |  |  |  | $2,108.4 |  |  |  | $2,597.8 |  |  |  | $1.0 |  |  |  | ($10.0 | ) |  |  | $200.0 |  |  |  | $4,899.6 |
IPL | Total IPL Common Equity |  |  |  |
|  |  | Additional |  |  |  | Cumulative |  |
| Common |  | Paid-In |  | Retained |  | Preferred |  | Total
| Stock |  | Capital |  | Earnings |  | Stock |  | Equity
Three Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2020 |  | $33.4 |  |  |  | $2,447.8 |  |  |  | $914.2 |  |  |  | $200.0 |  |  |  | $3,595.4 |
Net income available for common stock |  |  |  |  | 59.8 |  |  |  |  | 59.8 |
Common stock dividends |  |  |  |  | (59.1 | ) |  |  |  | (59.1 | )
Capital contributions from parent |  |  | 75.0 |  |  |  |  |  |  | 75.0 |
Ending balance, June 30, 2020 |  | $33.4 |  |  |  | $2,522.8 |  |  |  | $914.9 |  |  |  | $200.0 |  |  |  | $3,671.1 |
Three Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2019 |  | $33.4 |  |  |  | $2,322.8 |  |  |  | $785.8 |  |  |  | $200.0 |  |  |  | $3,342.0 |
Net income available for common stock |  |  |  |  | 45.0 |  |  |  |  | 45.0 |
Common stock dividends |  |  |  |  | (41.9 | ) |  |  |  | (41.9 | )
Ending balance, June 30, 2019 |  | $33.4 |  |  |  | $2,322.8 |  |  |  | $788.9 |  |  |  | $200.0 |  |  |  | $3,345.1 |
IPL | Total IPL Common Equity |  |  |  |
|  |  | Additional |  |  |  | Cumulative |  |
| Common |  | Paid-In |  | Retained |  | Preferred |  | Total
| Stock |  | Capital |  | Earnings |  | Stock |  | Equity
Six Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2019 |  | $33.4 |  |  |  | $2,347.8 |  |  |  | $890.6 |  |  |  | $200.0 |  |  |  | $3,471.8 |
Net income available for common stock |  |  |  |  | 142.4 |  |  |  |  | 142.4 |
Common stock dividends |  |  |  |  | (118.1 | ) |  |  |  | (118.1 | )
Capital contributions from parent |  |  | 175.0 |  |  |  |  |  |  | 175.0 |
Ending balance, June 30, 2020 |  | $33.4 |  |  |  | $2,522.8 |  |  |  | $914.9 |  |  |  | $200.0 |  |  |  | $3,671.1 |
Six Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2018 |  | $33.4 |  |  |  | $2,222.8 |  |  |  | $774.5 |  |  |  | $200.0 |  |  |  | $3,230.7 |
Net income available for common stock |  |  |  |  | 98.3 |  |  |  |  | 98.3 |
Common stock dividends |  |  |  |  | (83.9 | ) |  |  |  | (83.9 | )
Capital contributions from parent |  |  | 100.0 |  |  |  |  |  |  | 100.0 |
Ending balance, June 30, 2019 |  | $33.4 |  |  |  | $2,322.8 |  |  |  | $788.9 |  |  |  | $200.0 |  |  |  | $3,345.1 |
WPL |  |  | Additional |  |  |  | Total
| Common |  | Paid-In |  | Retained |  | Common
| Stock |  | Capital |  | Earnings |  | Equity
Three Months Ended June 30, 2020 |  |  |  |  |  |  |
Beginning balance, March 31, 2020 |  | $66.2 |  |  |  | $1,459.0 |  |  |  | $910.9 |  |  |  | $2,436.1 |
Net income |  |  |  |  | 57.6 |  |  | 57.6 |
Common stock dividends |  |  |  |  | (41.9 | ) |  | (41.9 | )
Ending balance, June 30, 2020 |  | $66.2 |  |  |  | $1,459.0 |  |  |  | $926.6 |  |  |  | $2,451.8 |
Three Months Ended June 30, 2019 |  |  |  |  |  |  |
Beginning balance, March 31, 2019 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $804.0 |  |  |  | $2,179.2 |
Net income |  |  |  |  | 42.0 |  |  | 42.0 |
Common stock dividends |  |  |  |  | (36.0 | ) |  | (36.0 | )
Ending balance, June 30, 2019 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $810.0 |  |  |  | $2,185.2 |
WPL |  |  | Additional |  |  |  | Total
| Common |  | Paid-In |  | Retained |  | Common
| Stock |  | Capital |  | Earnings |  | Equity
Six Months Ended June 30, 2020 |  |  |  |  |  |  |
Beginning balance, December 31, 2019 |  | $66.2 |  |  |  | $1,434.0 |  |  |  | $863.4 |  |  |  | $2,363.6 |
Net income |  |  |  |  | 147.2 |  |  | 147.2 |
Common stock dividends |  |  |  |  | (84.0 | ) |  | (84.0 | )
Capital contributions from parent |  |  | 25.0 |  |  |  |  | 25.0 |
Ending balance, June 30, 2020 |  | $66.2 |  |  |  | $1,459.0 |  |  |  | $926.6 |  |  |  | $2,451.8 |
Six Months Ended June 30, 2019 |  |  |  |  |  |  |
Beginning balance, December 31, 2018 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $774.3 |  |  |  | $2,149.5 |
Net income |  |  |  |  | 107.7 |  |  | 107.7 |
Common stock dividends |  |  |  |  | (72.0 | ) |  | (72.0 | )
Ending balance, June 30, 2019 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $810.0 |  |  |  | $2,185.2 |
WPL [Member] |
Common Equity [Line Items] |
Common Equity | COMMON EQUITY Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows:
Shares outstanding, January 1, 2020 | 245,022,800 |
Equity forward agreements | 4,275,127 |
Shareowner Direct Plan | 248,220 |
Equity-based compensation plans | 98,205 |
Shares outstanding, June 30, 2020 | 249,644,352 |
Equity Forward Agreements - In November 2019, Alliant Energy entered into forward sale agreements with a counterparty in connection with a public offering of 4,275,127 shares of Alliant Energy common stock. The initial forward sale price of $52.235 per share was subject to daily adjustment based on a floating interest rate factor, and decreased by other fixed amounts specified in the forward sale agreements. In the first quarter of 2020, Alliant Energy settled $222 million under the forward sale agreements by delivering 4,275,127 shares of newly issued Alliant Energy common stock at a weighted average forward sale price of $51.98 per share. Alliant Energy used the net proceeds from the settlements for general corporate purposes. 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 |  | Income (Loss) |  | Trust |  | of IPL |  | Equity
Three Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2020 |  | $2.5 |  |  |  | $2,674.1 |  |  |  | $2,833.7 |  |  |  | $2.0 |  |  |  | ($9.9 | ) |  |  | $200.0 |  |  |  | $5,702.4 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 134.4 |  |  |  |  |  |  |  |  | 134.4 |
Common stock dividends ($0.38 per share) |  |  |  |  | (94.6 | ) |  |  |  |  |  |  |  | (94.6 | )
Shareowner Direct Plan issuances |  |  |  | 6.4 |  |  |  |  |  |  |  |  |  |  | 6.4 |
Equity-based compensation plans and other |  |  | 2.6 |  |  |  |  |  |  | (0.3 | ) |  |  |  | 2.3 |
Other comprehensive loss, net of tax |  |  |  |  |  |  | (2.6 | ) |  |  |  |  |  | (2.6 | )
Ending balance, June 30, 2020 |  | $2.5 |  |  |  | $2,683.1 |  |  |  | $2,873.5 |  |  |  | ($0.6 | ) |  |  | ($10.2 | ) |  |  | $200.0 |  |  |  | $5,748.3 |
Three Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2019 |  | $2.4 |  |  |  | $2,100.0 |  |  |  | $2,587.3 |  |  |  | $2.4 |  |  |  | ($9.7 | ) |  |  | $200.0 |  |  |  | $4,882.4 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 94.6 |  |  |  |  |  |  |  |  | 94.6 |
Common stock dividends ($0.355 per share) |  |  |  |  | (84.1 | ) |  |  |  |  |  |  |  | (84.1 | )
Shareowner Direct Plan issuances |  |  |  | 6.0 |  |  |  |  |  |  |  |  |  |  | 6.0 |
Equity-based compensation plans and other |  |  | 2.4 |  |  |  |  |  |  | (0.3 | ) |  |  |  | 2.1 |
Other comprehensive loss, net of tax |  |  |  |  |  |  | (1.4 | ) |  |  |  |  |  | (1.4 | )
Ending balance, June 30, 2019 |  | $2.4 |  |  |  | $2,108.4 |  |  |  | $2,597.8 |  |  |  | $1.0 |  |  |  | ($10.0 | ) |  |  | $200.0 |  |  |  | $4,899.6 |
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 |  | Income (Loss) |  | Trust |  | of IPL |  | Equity
Six Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2019 |  | $2.5 |  |  |  | $2,445.9 |  |  |  | $2,765.4 |  |  |  | $1.3 |  |  |  | ($10.0 | ) |  |  | $200.0 |  |  |  | $5,405.1 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 304.4 |  |  |  |  |  |  |  |  | 304.4 |
Common stock dividends ($0.76 per share) |  |  |  |  | (187.6 | ) |  |  |  |  |  |  |  | (187.6 | )
Equity forward settlements and Shareowner Direct Plan issuances |  |  |  | 234.8 |  |  |  |  |  |  |  |  |  |  | 234.8 |
Equity-based compensation plans and other |  |  | 2.4 |  |  |  |  |  |  | (0.2 | ) |  |  |  | 2.2 |
Adoption of new accounting standard, net of tax (refer to Note 1(d)) |  |  |  |  | (8.7 | ) |  |  |  |  |  |  |  | (8.7 | )
Other comprehensive loss, net of tax |  |  |  |  |  |  | (1.9 | ) |  |  |  |  |  | (1.9 | )
Ending balance, June 30, 2020 |  | $2.5 |  |  |  | $2,683.1 |  |  |  | $2,873.5 |  |  |  | ($0.6 | ) |  |  | ($10.2 | ) |  |  | $200.0 |  |  |  | $5,748.3 |
Six Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2018 |  | $2.4 |  |  |  | $2,045.5 |  |  |  | $2,545.9 |  |  |  | $1.7 |  |  |  | ($9.8 | ) |  |  | $200.0 |  |  |  | $4,785.7 |
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 219.7 |  |  |  |  |  |  |  |  | 219.7 |
Common stock dividends ($0.71 per share) |  |  |  |  | (167.8 | ) |  |  |  |  |  |  |  | (167.8 | )
Equity forward settlements and Shareowner Direct Plan issuances |  |  | 60.6 |  |  |  |  |  |  |  |  |  |  | 60.6 |
Equity-based compensation plans and other |  |  | 2.3 |  |  |  |  |  |  | (0.2 | ) |  |  |  | 2.1 |
Other comprehensive loss, net of tax |  |  |  |  |  |  | (0.7 | ) |  |  |  |  |  | (0.7 | )
Ending balance, June 30, 2019 |  | $2.4 |  |  |  | $2,108.4 |  |  |  | $2,597.8 |  |  |  | $1.0 |  |  |  | ($10.0 | ) |  |  | $200.0 |  |  |  | $4,899.6 |
IPL | Total IPL Common Equity |  |  |  |
|  |  | Additional |  |  |  | Cumulative |  |
| Common |  | Paid-In |  | Retained |  | Preferred |  | Total
| Stock |  | Capital |  | Earnings |  | Stock |  | Equity
Three Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2020 |  | $33.4 |  |  |  | $2,447.8 |  |  |  | $914.2 |  |  |  | $200.0 |  |  |  | $3,595.4 |
Net income available for common stock |  |  |  |  | 59.8 |  |  |  |  | 59.8 |
Common stock dividends |  |  |  |  | (59.1 | ) |  |  |  | (59.1 | )
Capital contributions from parent |  |  | 75.0 |  |  |  |  |  |  | 75.0 |
Ending balance, June 30, 2020 |  | $33.4 |  |  |  | $2,522.8 |  |  |  | $914.9 |  |  |  | $200.0 |  |  |  | $3,671.1 |
Three Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |
Beginning balance, March 31, 2019 |  | $33.4 |  |  |  | $2,322.8 |  |  |  | $785.8 |  |  |  | $200.0 |  |  |  | $3,342.0 |
Net income available for common stock |  |  |  |  | 45.0 |  |  |  |  | 45.0 |
Common stock dividends |  |  |  |  | (41.9 | ) |  |  |  | (41.9 | )
Ending balance, June 30, 2019 |  | $33.4 |  |  |  | $2,322.8 |  |  |  | $788.9 |  |  |  | $200.0 |  |  |  | $3,345.1 |
IPL | Total IPL Common Equity |  |  |  |
|  |  | Additional |  |  |  | Cumulative |  |
| Common |  | Paid-In |  | Retained |  | Preferred |  | Total
| Stock |  | Capital |  | Earnings |  | Stock |  | Equity
Six Months Ended June 30, 2020 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2019 |  | $33.4 |  |  |  | $2,347.8 |  |  |  | $890.6 |  |  |  | $200.0 |  |  |  | $3,471.8 |
Net income available for common stock |  |  |  |  | 142.4 |  |  |  |  | 142.4 |
Common stock dividends |  |  |  |  | (118.1 | ) |  |  |  | (118.1 | )
Capital contributions from parent |  |  | 175.0 |  |  |  |  |  |  | 175.0 |
Ending balance, June 30, 2020 |  | $33.4 |  |  |  | $2,522.8 |  |  |  | $914.9 |  |  |  | $200.0 |  |  |  | $3,671.1 |
Six Months Ended June 30, 2019 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2018 |  | $33.4 |  |  |  | $2,222.8 |  |  |  | $774.5 |  |  |  | $200.0 |  |  |  | $3,230.7 |
Net income available for common stock |  |  |  |  | 98.3 |  |  |  |  | 98.3 |
Common stock dividends |  |  |  |  | (83.9 | ) |  |  |  | (83.9 | )
Capital contributions from parent |  |  | 100.0 |  |  |  |  |  |  | 100.0 |
Ending balance, June 30, 2019 |  | $33.4 |  |  |  | $2,322.8 |  |  |  | $788.9 |  |  |  | $200.0 |  |  |  | $3,345.1 |
WPL |  |  | Additional |  |  |  | Total
| Common |  | Paid-In |  | Retained |  | Common
| Stock |  | Capital |  | Earnings |  | Equity
Three Months Ended June 30, 2020 |  |  |  |  |  |  |
Beginning balance, March 31, 2020 |  | $66.2 |  |  |  | $1,459.0 |  |  |  | $910.9 |  |  |  | $2,436.1 |
Net income |  |  |  |  | 57.6 |  |  | 57.6 |
Common stock dividends |  |  |  |  | (41.9 | ) |  | (41.9 | )
Ending balance, June 30, 2020 |  | $66.2 |  |  |  | $1,459.0 |  |  |  | $926.6 |  |  |  | $2,451.8 |
Three Months Ended June 30, 2019 |  |  |  |  |  |  |
Beginning balance, March 31, 2019 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $804.0 |  |  |  | $2,179.2 |
Net income |  |  |  |  | 42.0 |  |  | 42.0 |
Common stock dividends |  |  |  |  | (36.0 | ) |  | (36.0 | )
Ending balance, June 30, 2019 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $810.0 |  |  |  | $2,185.2 |
WPL |  |  | Additional |  |  |  | Total
| Common |  | Paid-In |  | Retained |  | Common
| Stock |  | Capital |  | Earnings |  | Equity
Six Months Ended June 30, 2020 |  |  |  |  |  |  |
Beginning balance, December 31, 2019 |  | $66.2 |  |  |  | $1,434.0 |  |  |  | $863.4 |  |  |  | $2,363.6 |
Net income |  |  |  |  | 147.2 |  |  | 147.2 |
Common stock dividends |  |  |  |  | (84.0 | ) |  | (84.0 | )
Capital contributions from parent |  |  | 25.0 |  |  |  |  | 25.0 |
Ending balance, June 30, 2020 |  | $66.2 |  |  |  | $1,459.0 |  |  |  | $926.6 |  |  |  | $2,451.8 |
Six Months Ended June 30, 2019 |  |  |  |  |  |  |
Beginning balance, December 31, 2018 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $774.3 |  |  |  | $2,149.5 |
Net income |  |  |  |  | 107.7 |  |  | 107.7 |
Common stock dividends |  |  |  |  | (72.0 | ) |  | (72.0 | )
Ending balance, June 30, 2019 |  | $66.2 |  |  |  | $1,309.0 |  |  |  | $810.0 |  |  |  | $2,185.2 |

X
- Definition Common Equity [Line Items] + References No definition available. + Details
Name: | lnt_CommonEquityLineItems
Namespace Prefix: | lnt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -URI http://asc.fasb.org/topic&trid=2208762 + Details
Name: | us-gaap_StockholdersEquityNoteDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=lnt_IplMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=lnt_WplMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |