Pension Plan and Employee Benefits - Current and Non-Current Portions of the Other Benefits Liability (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Non-current	$ 244,811	$ 242,135
Other Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Current	4,061	4,061
Non-current	37,879	39,142
CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Non-current	173,559	173,747
CLECO POWER | Other Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Current	3,525	3,525
Non-current	$ 33,013	$ 34,033