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v3.23.2

Fair Value Measurements (Fair Value Measurements) (Details) - USD ($) $ in Millions | Jun. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Assets: |  |
Money market fund investments | $ 6 | $ 10
Deferred proceeds | 175 | 185
Liabilities: |  |
Long-term debt (incl. current maturities) | 7,951 | 7,339
IPL [Member] |  |
Assets: |  |
Money market fund investments | 6 | 10
Deferred proceeds | 175 | 185
Liabilities: |  |
Long-term debt (incl. current maturities) | 3,321 | 3,228
WPL [Member] |  |
Liabilities: |  |
Long-term debt (incl. current maturities) | 2,875 | 2,542
Commodity Contracts [Member] |  |
Assets: |  |
Derivatives | 147 | 237
Liabilities: |  |
Derivatives | 97 | 79
Commodity Contracts [Member] | IPL [Member] |  |
Assets: |  |
Derivatives | 95 | 138
Liabilities: |  |
Derivatives | 37 | 46
Commodity Contracts [Member] | WPL [Member] |  |
Assets: |  |
Derivatives | 52 | 99
Liabilities: |  |
Derivatives | 60 | 33
Interest Rate Swap [Member] |  |
Assets: |  |
Derivatives | 4 | 0
Level 1 [Member] |  |
Assets: |  |
Money market fund investments | 6 | 10
Deferred proceeds | 0 | 0
Liabilities: |  |
Long-term debt (incl. current maturities) | 0 | 0
Level 1 [Member] | IPL [Member] |  |
Assets: |  |
Money market fund investments | 6 | 10
Deferred proceeds | 0 | 0
Liabilities: |  |
Long-term debt (incl. current maturities) | 0 | 0
Level 1 [Member] | WPL [Member] |  |
Liabilities: |  |
Long-term debt (incl. current maturities) | 0 | 0
Level 1 [Member] | Commodity Contracts [Member] |  |
Assets: |  |
Derivatives | 0 | 0
Liabilities: |  |
Derivatives | 0 | 0
Level 1 [Member] | Commodity Contracts [Member] | IPL [Member] |  |
Assets: |  |
Derivatives | 0 | 0
Liabilities: |  |
Derivatives | 0 | 0
Level 1 [Member] | Commodity Contracts [Member] | WPL [Member] |  |
Assets: |  |
Derivatives | 0 | 0
Liabilities: |  |
Derivatives | 0 | 0
Level 1 [Member] | Interest Rate Swap [Member] |  |
Assets: |  |
Derivatives | 0 | 0
Level 2 [Member] |  |
Assets: |  |
Money market fund investments | 0 | 0
Deferred proceeds | 0 | 0
Liabilities: |  |
Long-term debt (incl. current maturities) | 7,950 | 7,338
Level 2 [Member] | IPL [Member] |  |
Assets: |  |
Money market fund investments | 0 | 0
Deferred proceeds | 0 | 0
Liabilities: |  |
Long-term debt (incl. current maturities) | 3,321 | 3,228
Level 2 [Member] | WPL [Member] |  |
Liabilities: |  |
Long-term debt (incl. current maturities) | 2,875 | 2,542
Level 2 [Member] | Commodity Contracts [Member] |  |
Assets: |  |
Derivatives | 80 | 206
Liabilities: |  |
Derivatives | 84 | 67
Level 2 [Member] | Commodity Contracts [Member] | IPL [Member] |  |
Assets: |  |
Derivatives | 44 | 111
Liabilities: |  |
Derivatives | 27 | 35
Level 2 [Member] | Commodity Contracts [Member] | WPL [Member] |  |
Assets: |  |
Derivatives | 36 | 95
Liabilities: |  |
Derivatives | 57 | 32
Level 2 [Member] | Interest Rate Swap [Member] |  |
Assets: |  |
Derivatives | 4 | 0
Level 3 [Member] |  |
Assets: |  |
Money market fund investments | 0 | 0
Deferred proceeds | 175 | 185
Liabilities: |  |
Long-term debt (incl. current maturities) | 1 | 1
Level 3 [Member] | IPL [Member] |  |
Assets: |  |
Money market fund investments | 0 | 0
Deferred proceeds | 175 | 185
Liabilities: |  |
Long-term debt (incl. current maturities) | 0 | 0
Level 3 [Member] | WPL [Member] |  |
Liabilities: |  |
Long-term debt (incl. current maturities) | 0 | 0
Level 3 [Member] | Commodity Contracts [Member] |  |
Assets: |  |
Derivatives | 67 | 31
Liabilities: |  |
Derivatives | 13 | 12
Level 3 [Member] | Commodity Contracts [Member] | IPL [Member] |  |
Assets: |  |
Derivatives | 51 | 27
Liabilities: |  |
Derivatives | 10 | 11
Level 3 [Member] | Commodity Contracts [Member] | WPL [Member] |  |
Assets: |  |
Derivatives | 16 | 4
Liabilities: |  |
Derivatives | 3 | 1
Level 3 [Member] | Interest Rate Swap [Member] |  |
Assets: |  |
Derivatives | 0 | 0
Carrying Amount [Member] |  |
Assets: |  |
Money market fund investments | 6 | 10
Deferred proceeds | 175 | 185
Liabilities: |  |
Long-term debt (incl. current maturities) | 8,595 | 8,076
Carrying Amount [Member] | IPL [Member] |  |
Assets: |  |
Money market fund investments | 6 | 10
Deferred proceeds | 175 | 185
Liabilities: |  |
Long-term debt (incl. current maturities) | 3,702 | 3,646
Carrying Amount [Member] | WPL [Member] |  |
Liabilities: |  |
Long-term debt (incl. current maturities) | 3,068 | 2,770
Carrying Amount [Member] | Commodity Contracts [Member] |  |
Assets: |  |
Derivatives | 147 | 237
Liabilities: |  |
Derivatives | 97 | 79
Carrying Amount [Member] | Commodity Contracts [Member] | IPL [Member] |  |
Assets: |  |
Derivatives | 95 | 138
Liabilities: |  |
Derivatives | 37 | 46
Carrying Amount [Member] | Commodity Contracts [Member] | WPL [Member] |  |
Assets: |  |
Derivatives | 52 | 99
Liabilities: |  |
Derivatives | 60 | 33
Carrying Amount [Member] | Interest Rate Swap [Member] |  |
Assets: |  |
Derivatives | $ 4 | $ 0

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