| BENEFIT PLANS NOTE 9(a) Pension and OPEB Plans - Net Periodic Benefit Costs - The components of net periodic benefit costs for sponsored defined benefit pension and OPEB plans for the three months ended March 31 are included below (in millions). For IPL and WPL, amounts represent those for their plan participants covered under plans they sponsor, as well as amounts directly assigned to them related to certain participants in the Alliant Energy and Corporate Services sponsored plans.
| | | | | | | | | | | | | | | | | | Defined Benefit Pension Plans | | OPEB Plans | Alliant Energy | 2020 | | 2019 | | 2020 | | 2019 | Service cost |
| $2.7 |
| |
| $2.4 |
| |
| $0.8 |
| |
| $0.8 |
| Interest cost | 10.8 |
| | 12.5 |
| | 1.8 |
| | 2.1 |
| Expected return on plan assets | (17.4 | ) | | (15.0 | ) | | (1.3 | ) | | (1.2 | ) | Amortization of prior service credit | (0.2 | ) | | (0.2 | ) | | — |
| | — |
| Amortization of actuarial loss | 8.6 |
| | 9.1 |
| | 0.8 |
| | 0.8 |
| Settlement losses (a) | 4.2 |
| | — |
| | — |
| | — |
| |
| $8.7 |
| |
| $8.8 |
| |
| $2.1 |
| |
| $2.5 |
|
| | | | | | | | | | | | | | | | | | Defined Benefit Pension Plans | | OPEB Plans | IPL | 2020 | | 2019 | | 2020 | | 2019 | Service cost |
| $1.7 |
| |
| $1.5 |
| |
| $0.3 |
| |
| $0.3 |
| Interest cost | 5.0 |
| | 5.7 |
| | 0.7 |
| | 0.8 |
| Expected return on plan assets | (8.1 | ) | | (7.0 | ) | | (1.0 | ) | | (0.9 | ) | Amortization of prior service credit | (0.1 | ) | | (0.1 | ) | | — |
| | — |
| Amortization of actuarial loss | 3.7 |
| | 3.9 |
| | 0.3 |
| | 0.4 |
| |
| $2.2 |
| |
| $4.0 |
| |
| $0.3 |
| |
| $0.6 |
|
| | | | | | | | | | | | | | | | | | Defined Benefit Pension Plans | | OPEB Plans | WPL | 2020 | | 2019 | | 2020 | | 2019 | Service cost |
| $1.0 |
| |
| $0.9 |
| |
| $0.3 |
| |
| $0.3 |
| Interest cost | 4.7 |
| | 5.4 |
| | 0.7 |
| | 0.8 |
| Expected return on plan assets | (7.6 | ) | | (6.5 | ) | | (0.2 | ) | | (0.1 | ) | Amortization of prior service credit | (0.1 | ) | | (0.1 | ) | | — |
| | — |
| Amortization of actuarial loss | 4.1 |
| | 4.4 |
| | 0.5 |
| | 0.4 |
| |
| $2.1 |
| |
| $4.1 |
| |
| $1.3 |
| |
| $1.4 |
|
| | (a) | Settlement losses related to payments made to retired executives of Alliant Energy. |
NOTE 9(b) Equity-based Compensation Plans - A summary of compensation expense, including amounts allocated to IPL and WPL, and the related income tax benefits recognized for share-based compensation awards for the three months ended March 31 was as follows (in millions): | | | | | | | | | | | | | | | | | | | | | | | | | | Alliant Energy | | IPL | | WPL | | 2020 | | 2019 | | 2020 | | 2019 | | 2020 | | 2019 | Compensation expense |
| $2.7 |
| |
| $4.7 |
| |
| $1.4 |
| |
| $2.6 |
| |
| $1.1 |
| |
| $1.8 |
| Income tax benefits | 0.7 |
| | 1.3 |
| | 0.4 |
| | 0.8 |
| | 0.3 |
| | 0.5 |
|
As of March 31, 2020, Alliant Energy’s, IPL’s and WPL’s total unrecognized compensation cost related to share-based compensation awards was $12.5 million, $7.0 million and $5.1 million, respectively, which is expected to be recognized over a weighted average period of between 1 year and 2 years.
For the three months ended March 31, 2020, performance shares, performance restricted stock units and restricted stock units were granted to key employees as follows. These shares and units will be paid out in shares of common stock, and are therefore accounted for as equity awards. As of March 31, 2020, 215,780 shares were included in the calculation of diluted EPS related to the nonvested equity awards. | | | | | | | | | | | Weighted Average | | Grants | | Grant Date Fair Value | Performance shares | 54,897 |
| |
| $64.04 |
| Performance restricted stock units | 54,897 |
| | 59.57 |
| Restricted stock units | 59,936 |
| | 59.57 |
|
|