Regulatory Assets and Liabilities - Narrative (Details) - CLECO POWER customer in Thousands, $ in Thousands			6 Months Ended
	Jun. 16, 2021 USD ($)	Mar. 29, 2021 USD ($)	Jun. 30, 2021 USD ($)	Feb. 17, 2021 customer	Feb. 14, 2021 customer	Dec. 31, 2020 USD ($)
Regulatory Liabilities [Line Items]
Regulatory assets			$ 583,746			$ 456,034
Affordability study
Regulatory Liabilities [Line Items]
Regulatory assets	$ 13,600		13,644			0
Regulatory asset, amortization period	10 years
Mine closure costs | Dolet Hills
Regulatory Liabilities [Line Items]
Regulatory assets			13,910			0
Madison Unit 3 property taxes
Regulatory Liabilities [Line Items]
Regulatory assets			$ 4,181			0
Regulatory asset, amortization period			12 months
Northlake Transmission Agreement, under collection
Regulatory Liabilities [Line Items]
Regulatory assets			$ 3,500
Regulatory asset, amortization period			12 months
Other deferred costs, primarily base rate case
Regulatory Liabilities [Line Items]
Regulatory assets			$ 4,100
Regulatory asset, amortization period			4 years
Coughlin Pipeline Project, deferred revenue
Regulatory Liabilities [Line Items]
Regulatory assets			$ 5,400
Regulatory asset, amortization period			4 years
St. Mary Clean Energy Center
Regulatory Liabilities [Line Items]
Regulatory assets			$ 6,959			$ 3,479
Regulatory asset, amortization period			4 years
Deferred storm restoration costs - Winter Storms Uri & Viola
Regulatory Liabilities [Line Items]
Capitalized storm restoration costs		$ 50,000	$ 8,400
Capitalized storm restoration costs, amortization period		12 months
Winter Storm Uri
Regulatory Liabilities [Line Items]
Number of customers affected with power outage | customer					11
Winter Storm Viola
Regulatory Liabilities [Line Items]
Number of customers affected with power outage | customer				43