Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees - Other Commitments (Details)		3 Months Ended	6 Months Ended
	Apr. 02, 2018 USD ($) Barge	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Jul. 31, 2018 USD ($)	Dec. 31, 2012 Barge	Dec. 31, 2008
Other Commitments [Line Items]
Energy investment, useful life			10 years
Tax benefits in excess of capital contributions		$ 18,300,000	$ 18,300,000
Period of recognition of gross investment amortization expense (in years)			10 years
Number of barges | Barge	42				42
Capital leased assets, number of units | Barge	42
Cleco Holdings
Other Commitments [Line Items]
Membership interest in U.S Bank New Markets Tax Credit Fund (in hundredths)						99.90%
Equity contributions to be made to the Fund			$ 285,500,000
Net tax benefits and cash to be received from the Fund			303,800,000
US Bancorp Community Development (USBCDC)
Other Commitments [Line Items]
Membership interest in U.S Bank New Markets Tax Credit Fund (in hundredths)						0.10%
Cleco Power
Other Commitments [Line Items]
Repayments of long-term capital lease obligations		700,000	700,000
Sublease revenue		$ 100,000	$ 100,000
Notes Payable to Banks | Subsequent Event | Bank Term Loan Agreement
Other Commitments [Line Items]
Debt amount				$ 300,000,000.0
Revolving Credit Facility | Subsequent Event
Other Commitments [Line Items]
Line of credit facility, maximum borrowing capacity				$ 100,000,000.0
Savage Inland Marine | Cleco Power
Other Commitments [Line Items]
Loans receivable, related party	$ 16,800,000