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Leases (Expected Maturities of Operating and Finance Lease Liabilities (Details) $ in Millions | Dec. 31, 2019 USD ($)
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Leases [Line Items] |
Operating Leases Liability, 2020 | $ 2
Operating Leases Liability, 2021 | 2
Operating Leases Liability, 2022 | 2
Operating Leases Liability, 2023 | 2
Operating Leases Liability, 2024 | 2
Operating Leases Liability, Thereafter | 10
Operating Leases Liability, Total | 20
Operating Leases Liability, Less: amount representing interest | 4
Operating Leases Liability, Present value of minimum lease payments | 16
IPL [Member] |
Leases [Line Items] |
Operating Leases Liability, 2020 | 1
Operating Leases Liability, 2021 | 1
Operating Leases Liability, 2022 | 1
Operating Leases Liability, 2023 | 1
Operating Leases Liability, 2024 | 1
Operating Leases Liability, Thereafter | 7
Operating Leases Liability, Total | 12
Operating Leases Liability, Less: amount representing interest | 2
Operating Leases Liability, Present value of minimum lease payments | 10
WPL [Member] |
Leases [Line Items] |
Operating Leases Liability, 2020 | 1
Operating Leases Liability, 2021 | 1
Operating Leases Liability, 2022 | 1
Operating Leases Liability, 2023 | 1
Operating Leases Liability, 2024 | 1
Operating Leases Liability, Thereafter | 3
Operating Leases Liability, Total | 8
Operating Leases Liability, Less: amount representing interest | 2
Operating Leases Liability, Present value of minimum lease payments | 6
Sheboygan Falls Energy Facility [Member] | WPL [Member] |
Leases [Line Items] |
Finance Lease Liability, 2020 | 15
Finance Lease Liability, 2021 | 15
Finance Lease Liability, 2022 | 15
Finance Lease Liability, 2023 | 15
Finance Lease Liability, 2024 | 15
Finance Lease Liability, Thereafter | 5
Finance Lease Liability, Total | 80
Finance Lease Liability, Less: amount representing interest | 20
Finance Lease Liability, Present value of minimum lease payments | $ 60

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