Fair Value Accounting - Narrative (Details) MWh in Millions, MMBTU in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2020 MWh	Sep. 30, 2020 MMBTU	Dec. 31, 2019 MWh	Dec. 31, 2019 MMBTU
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Volume outstanding	24.1	63.9	14.6	58.5
CLECO POWER
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Volume outstanding	14.8		9.2

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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