Pension Plan and Employee Benefits, SERP (Details) - SERP Benefits [Member] - USD ($) $ in Thousands	3 Months Ended			6 Months Ended	9 Months Ended
	Sep. 30, 2016	Apr. 12, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Apr. 13, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.47%	4.60%		3.47%	3.47%		4.15%
Cleco Power [Member]
Components of periodic benefit costs [Abstract]
Total benefit cost	$ 300		$ 600		$ 1,100	$ 1,700
Current portion of SERP liability	905			$ 905	905			$ 1,000
Noncurrent portion of SERP liability	18,188			18,188	18,188			21,321
Successor [Member]
Components of periodic benefit costs [Abstract]
Service cost	213			277
Interest cost	839			1,543
Prior period service (credit) cost	(9)			(42)
Net loss	511			1,120
Net periodic benefit cost				2,898
Curtailments				0
Special/contractual termination benefits				0
Total benefit cost	1,554			2,898
Current portion of SERP liability	4,389			4,389	4,389
Noncurrent portion of SERP liability	$ 82,143			$ 82,143	$ 82,143
Predecessor [Member]
Components of periodic benefit costs [Abstract]
Service cost		$ 702	676			2,029
Interest cost		900	764			2,292
Prior period service (credit) cost		17	14			40
Net loss		574	743			2,230
Net periodic benefit cost		2,193				6,591
Curtailments		3,602				0
Special/contractual termination benefits		3,222				0
Total benefit cost		$ 9,017	$ 2,197			$ 6,591
Current portion of SERP liability								3,238
Noncurrent portion of SERP liability								$ 69,049