Pension Plan and Employee Benefits - Current and Non-Current Portions of the Other Benefits Liability (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Non-current	$ 285,964	$ 283,075
CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Non-current	209,809	206,270
Other Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Current	4,401	4,401
Non-current	47,874	48,321
Other Benefits Plan | CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Current	3,815	3,815
Non-current	$ 41,673	$ 42,080