Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees - Litigation (Details) $ in Thousands				1 Months Ended						3 Months Ended		6 Months Ended		24 Months Ended	30 Months Ended
	Jun. 01, 2020	May 21, 2020	Jan. 01, 2020	Mar. 31, 2020 USD ($)	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015 USD ($)	Dec. 31, 2014 claim	Nov. 30, 2014 claim	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	May 31, 2016 complaint	Mar. 29, 2021 USD ($)	Sep. 27, 2019 recommendation finding	Dec. 31, 2017 USD ($)
Loss Contingencies [Line Items]
Electric customer credits										$ 18,517	$ 9,100	$ 39,494	$ 17,593
Loss contingency, estimate of possible loss										3,800		3,800
South Central Generating
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss										1,500		1,500
Indemnification asset																		$ 10,000
Contingent liability																		$ 10,000
FERC | MISO Transmission Rates
Loss Contingencies [Line Items]
Public utilities, requested rate increase (decrease), percentage (in hundredths)									0.50%
Gulf Coast Spinning start up costs
Loss Contingencies [Line Items]
Allegations by plaintiff, failure to perform							$ 6,500
Gulf Coast Spinning construction of cotton spinning facility
Loss Contingencies [Line Items]
Allegations by plaintiff, failure to perform							$ 60,000
Actions filed in the 9th Judicial District Court | Alleged Breach of Fiduciary Duties
Loss Contingencies [Line Items]
Number of actions filed | claim									4
Actions filed in the Civil District Court | Alleged Breach of Fiduciary Duties
Loss Contingencies [Line Items]
Number of actions filed | claim								3	3
CLECO POWER
Loss Contingencies [Line Items]
Electric customer credits										18,762	$ 9,100	39,738	$ 17,440
CLECO POWER | Deferred storm restoration costs - Winter Storms Uri & Viola
Loss Contingencies [Line Items]
Capitalized storm restoration costs										8,400		8,400				$ 50,000
CLECO POWER | LPSC 2018-2019 Fuel Audit
Loss Contingencies [Line Items]
Fuel expense														$ 565,800
CLECO POWER | MISO Transmission Rates
Loss Contingencies [Line Items]
Public utilities, proposed return on equity, percentage (in hundredths)	10.52%		10.38%		10.32%	9.70%
CLECO POWER | LPSC
Loss Contingencies [Line Items]
Environmental expense				$ 26,200
CLECO POWER | FERC
Loss Contingencies [Line Items]
Number of findings | finding																	12
Number of recommendations | recommendation																	59
Electric customer credits												4,400
Loss contingency, estimate of possible loss										$ 300		$ 300
CLECO POWER | FERC | MISO Transmission Rates
Loss Contingencies [Line Items]
Number of actions filed | complaint															2
Public utilities, approved return on equity, percentage (In hundredths)															12.38%
Public utilities, proposed return on equity, percentage (in hundredths)		10.02%			9.88%										6.68%