Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees - Litigation (Details) $ in Millions				1 Months Ended						12 Months Ended	24 Months Ended	30 Months Ended
	Mar. 11, 2020 USD ($)	Jan. 01, 2020	Nov. 07, 2019 USD ($)	Mar. 31, 2018 plaintiff	Sep. 30, 2016	Jun. 30, 2016 petition	Sep. 30, 2015 USD ($)	Dec. 31, 2014 claim	Nov. 30, 2014	Dec. 31, 2016 claim	Dec. 31, 2019 USD ($)	May 31, 2016	Mar. 31, 2020 USD ($)	Sep. 27, 2019 finding recommendation	Feb. 04, 2019 USD ($)	Mar. 31, 2017 generation_unit
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss													$ 5.1
South Central Generating
Loss Contingencies [Line Items]
Indemnification asset															$ 10.0
Contingent liability															$ 10.0
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							$ 6.5
Gulf Coast Spinning construction of cotton spinning facility
Loss Contingencies [Line Items]
Allegations by plaintiff, failure to perform							$ 60.0
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
Perry Bonin, Ace Chandler, and Michael Manuel, et al v. Sabine River Authority of Texas and Sabine River Authority of Louisiana, No. B-160173-C | Pending Litigation
Loss Contingencies [Line Items]
Number of generation units failed to repair | generation_unit																1
Number of generation units owned | generation_unit																2
Larry Addison, Et Al. V. Sabine River Authority Of Texas, Et Al | Pending Litigation
Loss Contingencies [Line Items]
Number of plaintiffs | plaintiff				26
CLECO POWER | LPSC 2018-2019 Fuel Audit
Loss Contingencies [Line Items]
Fuel expense											$ 565.8
CLECO POWER | LPSC Nov 2010-Dec 2015 EAC Audit
Loss Contingencies [Line Items]
Number of petitions filed with the U.S. Court of Appeals | petition						6
CLECO POWER | MISO Transmission Rates
Loss Contingencies [Line Items]
Public utilities, proposed return on equity, percentage (in hundredths)		10.38%			10.32%	9.70%
CLECO POWER | LPSC
Loss Contingencies [Line Items]
Environmental expense	$ 26.2
CLECO POWER | FERC
Loss Contingencies [Line Items]
Number of findings | finding														12
Number of recommendations | recommendation														59
Estimated refund interest amount			$ 3.5
Loss contingency, estimate of possible loss													$ 1.0
CLECO POWER | FERC | MISO Transmission Rates
Loss Contingencies [Line Items]
Public utilities, approved return on equity, percentage (In hundredths)												12.38%
Public utilities, proposed return on equity, percentage (in hundredths)					9.88%							6.68%