Pension Plan and Employee Benefits, SERP (Details) - USD ($) $ in Thousands			3 Months Ended				6 Months Ended
	Mar. 30, 2017	Apr. 12, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2016	Apr. 12, 2016	Jun. 30, 2017	Jun. 30, 2016	Mar. 29, 2017	Dec. 31, 2016
SERP Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate (in hundredths)	4.08%								4.22%
Components of periodic benefit costs [Abstract]
Current portion of SERP liability			$ 4,431				$ 4,431			$ 4,308
Noncurrent portion of SERP liability			77,029				77,029			73,738
Cleco Power | SERP Benefits [Member]
Components of periodic benefit costs [Abstract]
Total benefit cost			300	$ 300			600	$ 800
Current portion of SERP liability			939				939			885
Noncurrent portion of SERP liability			16,013				16,013			$ 15,145
Successor
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized			1,204		$ 1,110		2,872
Successor | SERP Benefits [Member]
Components of periodic benefit costs [Abstract]
Service cost			102		589		247
Interest cost			820		755		1,620
Prior period service (credit) cost			(29)		0		(68)
Net loss (gain)			624		0		1,025
Net periodic benefit cost			1,517		1,344		2,824
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments			0		0		0
Special/contractual termination benefits	$ 300		0		0		315
Total benefit cost			$ 1,517		$ 1,344		$ 3,139
Predecessor
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized		$ 219				$ 1,593
Predecessor | SERP Benefits [Member]
Components of periodic benefit costs [Abstract]
Service cost		119				702
Interest cost		169				900
Prior period service (credit) cost		3				17
Net loss (gain)		(81)				574
Net periodic benefit cost		210				2,193
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments		3,602				3,602
Special/contractual termination benefits		3,222				3,222
Total benefit cost		$ 7,034				$ 9,017