Fair Value Accounting - Narrative (Details) MWh in Millions, MMBTU in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2021 MWh	Mar. 31, 2021 MMBTU	Dec. 31, 2020 MWh	Dec. 31, 2020 MMBTU
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Volume outstanding	6.0	138.2	15.3	73.0
CLECO POWER
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Volume outstanding	3.7		9.5

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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