Regulatory Assets and Liabilities - Narrative (Details) - CLECO POWER customer in Thousands, $ in Thousands			1 Months Ended	9 Months Ended
	Jul. 01, 2022	Jul. 01, 2021	May 31, 2021	Sep. 30, 2021 USD ($)	Aug. 29, 2021 customer	Jun. 30, 2021 USD ($)	Jun. 16, 2021 USD ($)	Mar. 29, 2021 USD ($)	Feb. 17, 2021 customer	Feb. 14, 2021 customer	Dec. 31, 2020 USD ($)
Regulatory Liabilities [Line Items]
Regulatory assets				$ 721,426							$ 456,034
Affordability study
Regulatory Liabilities [Line Items]
Regulatory assets				13,438			$ 13,600				0
Regulatory asset, amortization period		10 years
Bayou Vista to Segura deferred revenue requirement
Regulatory Liabilities [Line Items]
Regulatory assets				287			$ 300				0
Bayou Vista to Segura deferred revenue requirement | Subsequent event | Forecast
Regulatory Liabilities [Line Items]
Regulatory asset, amortization period	12 months
Mine closure costs | Lignite Mine
Regulatory Liabilities [Line Items]
Regulatory assets				93,093							0
Madison Unit 3 property taxes
Regulatory Liabilities [Line Items]
Regulatory assets				$ 6,272							0
Regulatory asset, amortization period				12 months
Northlake Transmission Agreement, under collection
Regulatory Liabilities [Line Items]
Regulatory assets				$ 4,200		$ 5,700
Regulatory asset, amortization period		12 months
Other deferred costs, primarily base rate case
Regulatory Liabilities [Line Items]
Regulatory assets				3,900
Regulatory asset, amortization period		4 years
Coughlin Pipeline Project, deferred revenue
Regulatory Liabilities [Line Items]
Regulatory assets				5,100
Regulatory asset, amortization period		4 years
St. Mary Clean Energy Center
Regulatory Liabilities [Line Items]
Regulatory assets				6,524							$ 3,479
Regulatory asset, amortization period		4 years
Deferred storm restoration costs - Hurricane Ida
Regulatory Liabilities [Line Items]
Capitalized storm restoration costs				49,100
Number of customers affected with power outage | customer					100
Deferred storm restoration costs - Winter Storms Uri & Viola
Regulatory Liabilities [Line Items]
Capitalized storm restoration costs				$ 8,400				$ 50,000
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