Variable Interest Entities - Equity Method Investments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Total equity investment in investee	$ 18,172		$ 18,172		$ 18,172
Cleco Power
Schedule of Equity Method Investments [Line Items]
Purchase price	12,873		12,873		12,873
Cash contributions	6,399		6,399		6,399
Dividends	(1,100)		(1,100)		(1,100)
Total equity investment in investee	18,172		18,172		$ 18,172
Operating revenue	2,214	$ 392	4,134	$ 1,997
Operating expenses	2,214	392	4,134	1,997
Income before taxes	$ 0	$ 0	$ 0	$ 0