Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees, Other Commitments (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)	Aug. 31, 2017 Towboat	Dec. 31, 2016 USD ($)	Dec. 28, 2012 Towboat	Dec. 31, 2008
Other Commitments [Line Items]
Liability component contained in the net asset				$ 0.6
Tax Benefits in Excess of Capital Contributions	$ 11.8	$ 11.8
Period of recognition of gross investment amortization expense (in years)		10 years
Cleco Power [Member]
Other Commitments [Line Items]
Operating Lease, Expense	$ 0.3	$ 0.3
Maritime Equipment [Member] | Cleco Power [Member]
Other Commitments [Line Items]
Capital Leased Assets, Number of Units | Towboat					42
Operating Lease, Right-of-Use Asset | Towboat			42
Cleco Holdings [Member]
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		285.5
Net tax benefits and cash to be received from the Fund		303.8
Difference between equity contributions and total benefits received		$ 18.3