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Litigation (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019
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Loss Contingencies [Line Items] |  |
Potential liabilities related to litigation and environmental matters | $ 41.5 | $ 29.1
Loss Contingency, Receivable | 17.5 | 16.2
Loss Contingency, Regulated | $ 21.3 | $ 10.5

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