Storm Restoration (Details) customer in Thousands, $ in Thousands						1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 24, 2021 USD ($)	Feb. 14, 2021 USD ($) customer	Oct. 28, 2020 USD ($) customer	Oct. 09, 2020 USD ($) customer	Aug. 27, 2020 USD ($) customer	Feb. 28, 2021 USD ($)	Oct. 31, 2020 hurricane	Dec. 31, 2020 USD ($)	Feb. 22, 2021	Feb. 17, 2021 customer	Oct. 16, 2020	Sep. 18, 2020	Dec. 31, 2019 USD ($)
Deferred storm restoration costs - Hurricane Delta
Unusual or Infrequent Item, or Both [Line Items]
Total regulatory assets								$ 17,100
Deferred storm restoration costs - Hurricane Zeta
Unusual or Infrequent Item, or Both [Line Items]
Total regulatory assets								3,500
Cleco Power
Unusual or Infrequent Item, or Both [Line Items]
Total regulatory assets								456,034					$ 306,172
Cleco Power | Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Margin call, transmission amount	$ 21,000
Cleco Power | Deferred storm restoration costs - Hurricane Laura
Unusual or Infrequent Item, or Both [Line Items]
Total regulatory assets								54,406					0
Cleco Power | Deferred storm restoration costs - Hurricane Delta
Unusual or Infrequent Item, or Both [Line Items]
Total regulatory assets								17,051					0
Cleco Power | Deferred storm restoration costs - Hurricane Zeta
Unusual or Infrequent Item, or Both [Line Items]
Total regulatory assets								3,493					$ 0
Cleco Cajun | Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Margin call, transmission amount	$ 5,000
Natural Disasters and Other Casualty Events | Cleco Power
Unusual or Infrequent Item, or Both [Line Items]
Number of hurricanes | hurricane							3
Deferred storm restoration costs - Hurricane Laura
Unusual or Infrequent Item, or Both [Line Items]
Capitalized storm restoration costs								112,500
Deferred storm restoration costs - Hurricane Laura | Cleco Power
Unusual or Infrequent Item, or Both [Line Items]
Number of customers affected with power outage | customer					140,000
Percentage of customers affected by the hurricane with power restored												100.00%
Storm restoration costs					$ 180,300
Capitalization percentage					62.00%
Storm damage provision								9,400
Deferred storm restoration costs - Hurricane Delta
Unusual or Infrequent Item, or Both [Line Items]
Capitalized storm restoration costs								32,900
Deferred storm restoration costs - Hurricane Delta | Cleco Power
Unusual or Infrequent Item, or Both [Line Items]
Number of customers affected with power outage | customer				132,000
Percentage of customers affected by the hurricane with power restored											100.00%
Storm restoration costs				$ 50,700
Capitalization percentage				65.00%
Deferred storm restoration costs - Hurricane Zeta
Unusual or Infrequent Item, or Both [Line Items]
Capitalized storm restoration costs								$ 4,900
Deferred storm restoration costs - Hurricane Zeta | Cleco Power
Unusual or Infrequent Item, or Both [Line Items]
Number of customers affected with power outage | customer			73,000
Percentage of customers affected by the hurricane with power restored			100.00%
Storm restoration costs			$ 8,600
Capitalization percentage			57.00%
Winter storm Uri | Cleco Power | Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Number of customers affected with power outage | customer		11
Percentage of customers affected by the hurricane with power restored										100.00%
Winter storm Viola | Cleco Power | Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Number of customers affected with power outage | customer										43
Percentage of customers affected by the hurricane with power restored									100.00%
Winter Storms Uri & Viola | Cleco Power | Subsequent Event | MINIMUM
Unusual or Infrequent Item, or Both [Line Items]
Storm restoration costs						$ 9,000
Fuel and purchased power costs		$ 45,000
Winter Storms Uri & Viola | Cleco Power | Subsequent Event | MAXIMUM
Unusual or Infrequent Item, or Both [Line Items]
Storm restoration costs						$ 10,000
Fuel and purchased power costs		55,000
Winter Storms Uri & Viola | Cleco Cajun | Subsequent Event | MINIMUM
Unusual or Infrequent Item, or Both [Line Items]
Fuel and purchased power costs		10,000
Winter Storms Uri & Viola | Cleco Cajun | Subsequent Event | MAXIMUM
Unusual or Infrequent Item, or Both [Line Items]
Fuel and purchased power costs		$ 15,000