Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees, Other Commitments (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($)	Dec. 31, 2012 Barge	Dec. 31, 2008
Other Commitments [Line Items]
Tax benefits in excess of capital contributions	$ 18.3
Period of recognition of gross investment amortization expense (in years)	10 years
Number of barges | 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	$ 285.5
Net tax benefits and cash to be received from the Fund	$ 303.8
Energy investment, useful life	10 years
US Bancorp Community Development (USBCDC)
Other Commitments [Line Items]
Membership interest in U.S Bank New Markets Tax Credit Fund (in hundredths)			0.10%