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Leases | 6 Months Ended
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Jun. 30, 2019
Leases [Line Items] |
Operating Leases | LEASES Operating Leases - Alliant Energy’s, IPL’s and WPL’s operating leases primarily include leases of space on telecommunication towers and leases of property. Operating lease details are as follows (dollars in millions):
| June 30, 2019 |  |  |  |  |  |
| Alliant Energy |  | IPL |  | WPL |  |  |  |  |  |
Property, plant and equipment, net |  | $17 |  |  |  | $10 |  |  |  | $7 |  |  |  |  |  |  |
Other current liabilities |  | $2 |  |  |  | $1 |  |  |  | $1 |  |  |  |  |  |  |
Other liabilities | 15 |  |  | 9 |  |  | 6 |  |  |  |  |  |  |
Total operating lease liabilities |  | $17 |  |  |  | $10 |  |  |  | $7 |  |  |  |  |  |  |
Weighted average remaining lease term | 11 years |  |  | 13 years |  |  | 10 years |  |  |  |  |  |  |
Weighted average discount rate | 4 | % |  | 4 | % |  | 4 | % |  |  |  |  |  |
| Three Months Ended |  | Six Months Ended
| June 30, 2019 |  | June 30, 2019
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Operating lease cost |  | $— |  |  |  | $— |  |  |  | $— |  |  |  | $1 |  |  |  | $— |  |  |  | $— |
Finance Lease - WPL’s finance lease is an agreement for WPL to lease the Sheboygan Falls Energy Facility from AEF’s Non-utility Generation business through 2025, the initial lease term. WPL is responsible for the operation of the EGU and has exclusive rights to its output. This finance lease contains two lease renewal periods, which are not included in the finance lease obligation, as well as an option to purchase the facility at the end of the initial lease term. WPL’s retail and wholesale rates include recovery of the Sheboygan Falls Energy Facility lease payments. WPL’s finance lease details are as follows (dollars in millions):
| June 30, 2019 |  |
Property, plant and equipment, net |  | $35 |  |  |
Other current liabilities |  | $8 |  |  |
Finance lease obligations - Sheboygan Falls Energy Facility | 56 |  |  |
Total finance lease liabilities |  | $64 |  |  |
Remaining lease term | 6 years |  |  |
Discount rate | 11 | % |  |
| Three Months Ended |  | Six Months Ended
| June 30, 2019 |  | June 30, 2019
Depreciation expense |  | $2 |  |  |  | $3 |
Interest expense | 2 |  |  | 4 |
Total finance lease expense |  | $4 |  |  |  | $7 |
Expected Maturities - As of June 30, 2019, expected maturities of lease liabilities were as follows (in millions):
| Remainder of 2019 |  | 2020 |  | 2021 |  | 2022 |  | 2023 |  | Thereafter |  | Total |  | Less: amount representing interest |  | Present value of minimum lease payments
Operating Leases: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Alliant Energy |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $13 |  |  |  | $23 |  |  |  | $6 |  |  |  | $17 |
IPL | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 9 |  |  | 14 |  |  | 4 |  |  | 10 |
WPL | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 4 |  |  | 9 |  |  | 2 |  |  | 7 |
WPL’s Finance Lease: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sheboygan Falls Energy Facility | 7 |  |  | 15 |  |  | 15 |  |  | 15 |  |  | 15 |  |  | 20 |  |  | 87 |  |  | 23 |  |  | 64 |
Prior period amounts have not been restated to reflect the adoption of the new lease accounting standard and continue to be reported under the accounting standards in effect for those periods. As of December 31, 2018, future minimum operating (excluding contingent rentals) and capital lease payments were as follows (in millions):
| 2019 |  | 2020 |  | 2021 |  | 2022 |  | 2023 |  | Thereafter |  | Total |  | Less: amount representing interest |  | Present value of minimum capital lease payments
Operating Leases: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Alliant Energy |  | $5 |  |  |  | $5 |  |  |  | $3 |  |  |  | $3 |  |  |  | $2 |  |  |  | $12 |  |  |  | $30 |  |  |  |  |
IPL | 3 |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 12 |  |  | 23 |  |  |  |  |
WPL | 2 |  |  | 3 |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | 6 |  |  |  |  |
WPL’s Capital Lease: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sheboygan Falls Energy Facility |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $19 |  |  |  | $94 |  |  |  | $26 |  |  |  | $68 |
IPL [Member] |
Leases [Line Items] |
Operating Leases | LEASES Operating Leases - Alliant Energy’s, IPL’s and WPL’s operating leases primarily include leases of space on telecommunication towers and leases of property. Operating lease details are as follows (dollars in millions):
| June 30, 2019 |  |  |  |  |  |
| Alliant Energy |  | IPL |  | WPL |  |  |  |  |  |
Property, plant and equipment, net |  | $17 |  |  |  | $10 |  |  |  | $7 |  |  |  |  |  |  |
Other current liabilities |  | $2 |  |  |  | $1 |  |  |  | $1 |  |  |  |  |  |  |
Other liabilities | 15 |  |  | 9 |  |  | 6 |  |  |  |  |  |  |
Total operating lease liabilities |  | $17 |  |  |  | $10 |  |  |  | $7 |  |  |  |  |  |  |
Weighted average remaining lease term | 11 years |  |  | 13 years |  |  | 10 years |  |  |  |  |  |  |
Weighted average discount rate | 4 | % |  | 4 | % |  | 4 | % |  |  |  |  |  |
| Three Months Ended |  | Six Months Ended
| June 30, 2019 |  | June 30, 2019
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Operating lease cost |  | $— |  |  |  | $— |  |  |  | $— |  |  |  | $1 |  |  |  | $— |  |  |  | $— |
Finance Lease - WPL’s finance lease is an agreement for WPL to lease the Sheboygan Falls Energy Facility from AEF’s Non-utility Generation business through 2025, the initial lease term. WPL is responsible for the operation of the EGU and has exclusive rights to its output. This finance lease contains two lease renewal periods, which are not included in the finance lease obligation, as well as an option to purchase the facility at the end of the initial lease term. WPL’s retail and wholesale rates include recovery of the Sheboygan Falls Energy Facility lease payments. WPL’s finance lease details are as follows (dollars in millions):
| June 30, 2019 |  |
Property, plant and equipment, net |  | $35 |  |  |
Other current liabilities |  | $8 |  |  |
Finance lease obligations - Sheboygan Falls Energy Facility | 56 |  |  |
Total finance lease liabilities |  | $64 |  |  |
Remaining lease term | 6 years |  |  |
Discount rate | 11 | % |  |
| Three Months Ended |  | Six Months Ended
| June 30, 2019 |  | June 30, 2019
Depreciation expense |  | $2 |  |  |  | $3 |
Interest expense | 2 |  |  | 4 |
Total finance lease expense |  | $4 |  |  |  | $7 |
Expected Maturities - As of June 30, 2019, expected maturities of lease liabilities were as follows (in millions):
| Remainder of 2019 |  | 2020 |  | 2021 |  | 2022 |  | 2023 |  | Thereafter |  | Total |  | Less: amount representing interest |  | Present value of minimum lease payments
Operating Leases: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Alliant Energy |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $13 |  |  |  | $23 |  |  |  | $6 |  |  |  | $17 |
IPL | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 9 |  |  | 14 |  |  | 4 |  |  | 10 |
WPL | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 4 |  |  | 9 |  |  | 2 |  |  | 7 |
WPL’s Finance Lease: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sheboygan Falls Energy Facility | 7 |  |  | 15 |  |  | 15 |  |  | 15 |  |  | 15 |  |  | 20 |  |  | 87 |  |  | 23 |  |  | 64 |
Prior period amounts have not been restated to reflect the adoption of the new lease accounting standard and continue to be reported under the accounting standards in effect for those periods. As of December 31, 2018, future minimum operating (excluding contingent rentals) and capital lease payments were as follows (in millions):
| 2019 |  | 2020 |  | 2021 |  | 2022 |  | 2023 |  | Thereafter |  | Total |  | Less: amount representing interest |  | Present value of minimum capital lease payments
Operating Leases: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Alliant Energy |  | $5 |  |  |  | $5 |  |  |  | $3 |  |  |  | $3 |  |  |  | $2 |  |  |  | $12 |  |  |  | $30 |  |  |  |  |
IPL | 3 |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 12 |  |  | 23 |  |  |  |  |
WPL | 2 |  |  | 3 |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | 6 |  |  |  |  |
WPL’s Capital Lease: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sheboygan Falls Energy Facility |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $19 |  |  |  | $94 |  |  |  | $26 |  |  |  | $68 |
WPL [Member] |
Leases [Line Items] |
Operating Leases | LEASES Operating Leases - Alliant Energy’s, IPL’s and WPL’s operating leases primarily include leases of space on telecommunication towers and leases of property. Operating lease details are as follows (dollars in millions):
| June 30, 2019 |  |  |  |  |  |
| Alliant Energy |  | IPL |  | WPL |  |  |  |  |  |
Property, plant and equipment, net |  | $17 |  |  |  | $10 |  |  |  | $7 |  |  |  |  |  |  |
Other current liabilities |  | $2 |  |  |  | $1 |  |  |  | $1 |  |  |  |  |  |  |
Other liabilities | 15 |  |  | 9 |  |  | 6 |  |  |  |  |  |  |
Total operating lease liabilities |  | $17 |  |  |  | $10 |  |  |  | $7 |  |  |  |  |  |  |
Weighted average remaining lease term | 11 years |  |  | 13 years |  |  | 10 years |  |  |  |  |  |  |
Weighted average discount rate | 4 | % |  | 4 | % |  | 4 | % |  |  |  |  |  |
| Three Months Ended |  | Six Months Ended
| June 30, 2019 |  | June 30, 2019
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Operating lease cost |  | $— |  |  |  | $— |  |  |  | $— |  |  |  | $1 |  |  |  | $— |  |  |  | $— |
Finance Lease - WPL’s finance lease is an agreement for WPL to lease the Sheboygan Falls Energy Facility from AEF’s Non-utility Generation business through 2025, the initial lease term. WPL is responsible for the operation of the EGU and has exclusive rights to its output. This finance lease contains two lease renewal periods, which are not included in the finance lease obligation, as well as an option to purchase the facility at the end of the initial lease term. WPL’s retail and wholesale rates include recovery of the Sheboygan Falls Energy Facility lease payments. WPL’s finance lease details are as follows (dollars in millions):
| June 30, 2019 |  |
Property, plant and equipment, net |  | $35 |  |  |
Other current liabilities |  | $8 |  |  |
Finance lease obligations - Sheboygan Falls Energy Facility | 56 |  |  |
Total finance lease liabilities |  | $64 |  |  |
Remaining lease term | 6 years |  |  |
Discount rate | 11 | % |  |
| Three Months Ended |  | Six Months Ended
| June 30, 2019 |  | June 30, 2019
Depreciation expense |  | $2 |  |  |  | $3 |
Interest expense | 2 |  |  | 4 |
Total finance lease expense |  | $4 |  |  |  | $7 |
Expected Maturities - As of June 30, 2019, expected maturities of lease liabilities were as follows (in millions):
| Remainder of 2019 |  | 2020 |  | 2021 |  | 2022 |  | 2023 |  | Thereafter |  | Total |  | Less: amount representing interest |  | Present value of minimum lease payments
Operating Leases: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Alliant Energy |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $13 |  |  |  | $23 |  |  |  | $6 |  |  |  | $17 |
IPL | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 9 |  |  | 14 |  |  | 4 |  |  | 10 |
WPL | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 4 |  |  | 9 |  |  | 2 |  |  | 7 |
WPL’s Finance Lease: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sheboygan Falls Energy Facility | 7 |  |  | 15 |  |  | 15 |  |  | 15 |  |  | 15 |  |  | 20 |  |  | 87 |  |  | 23 |  |  | 64 |
Prior period amounts have not been restated to reflect the adoption of the new lease accounting standard and continue to be reported under the accounting standards in effect for those periods. As of December 31, 2018, future minimum operating (excluding contingent rentals) and capital lease payments were as follows (in millions):
| 2019 |  | 2020 |  | 2021 |  | 2022 |  | 2023 |  | Thereafter |  | Total |  | Less: amount representing interest |  | Present value of minimum capital lease payments
Operating Leases: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Alliant Energy |  | $5 |  |  |  | $5 |  |  |  | $3 |  |  |  | $3 |  |  |  | $2 |  |  |  | $12 |  |  |  | $30 |  |  |  |  |
IPL | 3 |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 12 |  |  | 23 |  |  |  |  |
WPL | 2 |  |  | 3 |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | 6 |  |  |  |  |
WPL’s Capital Lease: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sheboygan Falls Energy Facility |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $19 |  |  |  | $94 |  |  |  | $26 |  |  |  | $68 |
Finance Leases | LEASES Operating Leases - Alliant Energy’s, IPL’s and WPL’s operating leases primarily include leases of space on telecommunication towers and leases of property. Operating lease details are as follows (dollars in millions):
| June 30, 2019 |  |  |  |  |  |
| Alliant Energy |  | IPL |  | WPL |  |  |  |  |  |
Property, plant and equipment, net |  | $17 |  |  |  | $10 |  |  |  | $7 |  |  |  |  |  |  |
Other current liabilities |  | $2 |  |  |  | $1 |  |  |  | $1 |  |  |  |  |  |  |
Other liabilities | 15 |  |  | 9 |  |  | 6 |  |  |  |  |  |  |
Total operating lease liabilities |  | $17 |  |  |  | $10 |  |  |  | $7 |  |  |  |  |  |  |
Weighted average remaining lease term | 11 years |  |  | 13 years |  |  | 10 years |  |  |  |  |  |  |
Weighted average discount rate | 4 | % |  | 4 | % |  | 4 | % |  |  |  |  |  |
| Three Months Ended |  | Six Months Ended
| June 30, 2019 |  | June 30, 2019
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Operating lease cost |  | $— |  |  |  | $— |  |  |  | $— |  |  |  | $1 |  |  |  | $— |  |  |  | $— |
Finance Lease - WPL’s finance lease is an agreement for WPL to lease the Sheboygan Falls Energy Facility from AEF’s Non-utility Generation business through 2025, the initial lease term. WPL is responsible for the operation of the EGU and has exclusive rights to its output. This finance lease contains two lease renewal periods, which are not included in the finance lease obligation, as well as an option to purchase the facility at the end of the initial lease term. WPL’s retail and wholesale rates include recovery of the Sheboygan Falls Energy Facility lease payments. WPL’s finance lease details are as follows (dollars in millions):
| June 30, 2019 |  |
Property, plant and equipment, net |  | $35 |  |  |
Other current liabilities |  | $8 |  |  |
Finance lease obligations - Sheboygan Falls Energy Facility | 56 |  |  |
Total finance lease liabilities |  | $64 |  |  |
Remaining lease term | 6 years |  |  |
Discount rate | 11 | % |  |
| Three Months Ended |  | Six Months Ended
| June 30, 2019 |  | June 30, 2019
Depreciation expense |  | $2 |  |  |  | $3 |
Interest expense | 2 |  |  | 4 |
Total finance lease expense |  | $4 |  |  |  | $7 |
Expected Maturities - As of June 30, 2019, expected maturities of lease liabilities were as follows (in millions):
| Remainder of 2019 |  | 2020 |  | 2021 |  | 2022 |  | 2023 |  | Thereafter |  | Total |  | Less: amount representing interest |  | Present value of minimum lease payments
Operating Leases: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Alliant Energy |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $2 |  |  |  | $13 |  |  |  | $23 |  |  |  | $6 |  |  |  | $17 |
IPL | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 9 |  |  | 14 |  |  | 4 |  |  | 10 |
WPL | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 1 |  |  | 4 |  |  | 9 |  |  | 2 |  |  | 7 |
WPL’s Finance Lease: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sheboygan Falls Energy Facility | 7 |  |  | 15 |  |  | 15 |  |  | 15 |  |  | 15 |  |  | 20 |  |  | 87 |  |  | 23 |  |  | 64 |
Prior period amounts have not been restated to reflect the adoption of the new lease accounting standard and continue to be reported under the accounting standards in effect for those periods. As of December 31, 2018, future minimum operating (excluding contingent rentals) and capital lease payments were as follows (in millions):
| 2019 |  | 2020 |  | 2021 |  | 2022 |  | 2023 |  | Thereafter |  | Total |  | Less: amount representing interest |  | Present value of minimum capital lease payments
Operating Leases: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Alliant Energy |  | $5 |  |  |  | $5 |  |  |  | $3 |  |  |  | $3 |  |  |  | $2 |  |  |  | $12 |  |  |  | $30 |  |  |  |  |
IPL | 3 |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 12 |  |  | 23 |  |  |  |  |
WPL | 2 |  |  | 3 |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | 6 |  |  |  |  |
WPL’s Capital Lease: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sheboygan Falls Energy Facility |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $15 |  |  |  | $19 |  |  |  | $94 |  |  |  | $26 |  |  |  | $68 |

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