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Regulatory Environment - PGL (Details) - Illinois Commerce Commission (ICC) - PGL $ in Millions | Dec. 31, 2020 Assurance | Jul. 31, 2019 USD ($) | Feb. 01, 2018 USD ($)
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Public Utilities, General Disclosures [Line Items] |  |  |
Rate base reduction from settlement of reconciliation |  | $ 7.0 | $ 5.4
Total refunds required to ratepayers from settlement |  | $ 7.3 | $ 4.7
Amount of assurance that PGL's QIP rider costs will be recoverable | Assurance | 0 |  |

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