Pension Plan and Employee Benefits, Amounts Recognized in Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Benefits Liability, Current	$ 4,061	$ 3,854
Other Benefits Liability, Noncurrent	39,142	40,196
SERP Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
SERP Liabilities, Current	4,471	4,308
SERP Liabilities, Noncurrent	79,868	73,738
Cleco Power [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Benefits Liability, Current	3,525	3,345
Other Benefits Liability, Noncurrent	34,033	34,892
Cleco Power [Member] | SERP Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
SERP Liabilities, Current	929	885
SERP Liabilities, Noncurrent	$ 16,589	$ 15,145