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Revenue Recognition (Allowance for Credit Losses) (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Allowance for Credit Loss | $ 23.9 | $ 23.5 | $ 52.3
Current period provisions | 36.0 | 7.2 |
Write-offs charged against allowance | (57.4) | (54.4) |
Recoveries of amounts previously written off | 21.8 | 18.4 |
Gas Distribution Operations |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Allowance for Credit Loss | 17.2 | 18.9 | 41.8
Current period provisions | 29.1 | 5.8 |
Write-offs charged against allowance | (52.1) | (46.7) |
Recoveries of amounts previously written off | 21.3 | 18.0 |
Electric Operations |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Allowance for Credit Loss | 5.9 | 3.8 | 9.7
Current period provisions | 6.9 | 1.4 |
Write-offs charged against allowance | (5.3) | (7.7) |
Recoveries of amounts previously written off | 0.5 | 0.4 |
Corporate and Other |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Allowance for Credit Loss | 0.8 | 0.8 | $ 0.8
Current period provisions | 0.0 | 0.0 |
Write-offs charged against allowance | 0.0 | 0.0 |
Recoveries of amounts previously written off | $ 0.0 | $ 0.0 |

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