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Receivables (Gross Write-offs For Accounts Receivable) (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
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Jun. 30, 2023 | Jun. 30, 2023
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Gross write-offs for accounts receivable, originated in 2022 | $ 3 | $ 8
Gross write-offs for accounts receivable, originated in 2023 | 2 | 2
IPL [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Gross write-offs for accounts receivable, originated in 2022 | 2 | 5
Gross write-offs for accounts receivable, originated in 2023 | 1 | 1
WPL [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Gross write-offs for accounts receivable, originated in 2022 | 1 | 3
Gross write-offs for accounts receivable, originated in 2023 | $ 1 | $ 1

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