Variable Interest Entities - Summarized Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Current assets	$ 664,892	$ 638,075
Total assets	7,725,569	7,476,298	$ 6,436,814
Current liabilities	524,612	511,339
Total liabilities and member’s equity	7,725,569	7,476,298
Operating revenue	1,498,146	1,639,605	1,231,044
Cleco Power
Variable Interest Entity [Line Items]
Current assets	394,097	392,798
Total assets	4,766,147	4,476,530
Current liabilities	380,706	359,259
Partners’ capital	18,145	34,145
Total liabilities and member’s equity	4,766,147	4,476,530
Operating revenue	1,032,292	1,168,370	1,241,596
Equity Method Investment, Nonconsolidated Investee or Group of Investees | Cleco Power
Variable Interest Entity [Line Items]
Current assets	16,805	2,239
Total assets	25,075	35,341
Current liabilities	369	1,196
Other liabilities	6,561	0
Partners’ capital	18,145	34,145
Total liabilities and member’s equity	25,075	35,341
Operating revenue	34,827	8,886	6,992
Operating expenses	34,827	8,886	6,992
Income before taxes	0	0	$ 0
Equity Method Investment, Nonconsolidated Investee or Group of Investees | Cleco Power | Property, plant, and equipment, net
Variable Interest Entity [Line Items]
Noncurrent assets	4,910	23,738
Equity Method Investment, Nonconsolidated Investee or Group of Investees | Cleco Power | Other assets
Variable Interest Entity [Line Items]
Noncurrent assets	$ 3,360	$ 9,364