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Regulatory Matters (Regulatory Liabilities) (Details) - USD ($) $ in Millions | Dec. 31, 2022 | Dec. 31, 2021
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Regulated Operations [Line Items] |  |
Regulatory Liabilities | $ 2,012.6 | $ 1,980.0
Regulatory Liability, Current | 236.8 | 137.4
Regulatory Liability, Noncurrent | 1,775.8 | 1,842.6
Deferred Derivative Gain (Loss) |  |
Regulated Operations [Line Items] |  |
Regulatory Liabilities | 90.0 | 34.2
Customer Assistance Programs |  |
Regulated Operations [Line Items] |  |
Regulatory Liabilities | 32.9 | 13.2
Rate Refunds |  |
Regulated Operations [Line Items] |  |
Regulatory Liabilities | 51.4 | 8.2
Overrecovered Gas And Fuel Costs |  |
Regulated Operations [Line Items] |  |
Regulatory Liabilities | 20.6 | 5.4
Cost Of Removal |  |
Regulated Operations [Line Items] |  |
Regulatory Liabilities | 675.9 | 749.5
Regulatory Effects Of Accounting For Income Taxes |  |
Regulated Operations [Line Items] |  |
Regulatory Liabilities | 996.3 | 1,040.8
Other Postretirement Costs |  |
Regulated Operations [Line Items] |  |
Regulatory Liabilities | 66.8 | 75.9
Other Liabilities |  |
Regulated Operations [Line Items] |  |
Regulatory Liabilities | $ 78.7 | $ 52.8

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- Definition The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 405 -Section 25 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394 + Details
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