Fair Value Accounting, Commodity Contracts (Details) $ in Thousands, MWh in Millions		3 Months Ended				6 Months Ended
	Apr. 12, 2016 USD ($)	Jun. 30, 2017 USD ($) MWh MMBTU	Jun. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Apr. 12, 2016 USD ($)	Jun. 30, 2017 USD ($) MWh MMBTU	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($) MWh MMBTU
Cleco Power
FTRs [Abstract]
Volume of FTRs Held (MWh) | MWh		20.0				20.0		9.0
Price Risk Derivative | Derivatives Not Designated As Hedging Instrument
FTRs, at Fair Value, Net [Abstract]
Commodity-related contracts, net		$ 17,943				$ 17,943		$ 7,683
Price Risk Derivative | Derivatives Not Designated As Hedging Instrument | Energy risk management assets
FTRs, at Fair Value, Net [Abstract]
FTRs in energy risk management assets		18,245				18,245		7,884
Price Risk Derivative | Derivatives Not Designated As Hedging Instrument | Energy risk management liabilities
FTRs, at Fair Value, Net [Abstract]
FTRs in Energy risk management liabilities		302				302		201
Price Risk Derivative | Cleco Power | Derivatives Not Designated As Hedging Instrument
FTRs, at Fair Value, Net [Abstract]
Commodity-related contracts, net		17,943				17,943		7,683
FTRs [Abstract]
Net gain (loss) on FTRs recognized in income		5,620	$ 6,581			10,118	$ 9,378
Price Risk Derivative | Cleco Power | Derivatives Not Designated As Hedging Instrument | Energy risk management assets
FTRs, at Fair Value, Net [Abstract]
FTRs in energy risk management assets		18,245				18,245		7,884
Price Risk Derivative | Cleco Power | Derivatives Not Designated As Hedging Instrument | Energy risk management liabilities
FTRs, at Fair Value, Net [Abstract]
FTRs in Energy risk management liabilities		302				302		$ 201
Price Risk Derivative | Cleco Power | Derivatives Not Designated As Hedging Instrument | Accumulated deferred fuel
FTRs [Abstract]
Unrealized gains (losses) associated with FTRs not recognized in income on derivatives		(2,500)	1,000			(2,500)	200
Price Risk Derivative | Cleco Power | Derivatives Not Designated As Hedging Instrument | Electric operations
FTRs [Abstract]
Gain on FTRs recognized in income		11,947	6,922			21,110	15,442
Price Risk Derivative | Cleco Power | Derivatives Not Designated As Hedging Instrument | Power purchased for utility customers
FTRs [Abstract]
Loss on FTRs recognized in income		$ (6,327)	$ (341)			$ (10,992)	$ (6,064)
Open Natural Gas Positions | Cleco Power
FTRs [Abstract]
Number of open natural gas positions | MMBTU		0				0		0
Predecessor | Price Risk Derivative | Derivatives Not Designated As Hedging Instrument
FTRs [Abstract]
Net gain (loss) on FTRs recognized in income	$ 5				$ 2,802
Predecessor | Price Risk Derivative | Derivatives Not Designated As Hedging Instrument | Accumulated deferred fuel
FTRs [Abstract]
Unrealized gains (losses) associated with FTRs not recognized in income on derivatives	(200)				(1,000)
Predecessor | Price Risk Derivative | Derivatives Not Designated As Hedging Instrument | Electric operations
FTRs [Abstract]
Gain on FTRs recognized in income	43				8,563
Predecessor | Price Risk Derivative | Derivatives Not Designated As Hedging Instrument | Power purchased for utility customers
FTRs [Abstract]
Loss on FTRs recognized in income	$ (38)				$ (5,761)
Successor | Price Risk Derivative | Derivatives Not Designated As Hedging Instrument
FTRs [Abstract]
Net gain (loss) on FTRs recognized in income		$ 5,620		$ 6,576		$ 10,118
Successor | Price Risk Derivative | Derivatives Not Designated As Hedging Instrument | Accumulated deferred fuel
FTRs [Abstract]
Unrealized gains (losses) associated with FTRs not recognized in income on derivatives		(2,500)		1,200		(2,500)
Successor | Price Risk Derivative | Derivatives Not Designated As Hedging Instrument | Electric operations
FTRs [Abstract]
Gain on FTRs recognized in income		11,947		6,879		21,110
Successor | Price Risk Derivative | Derivatives Not Designated As Hedging Instrument | Power purchased for utility customers
FTRs [Abstract]
Loss on FTRs recognized in income		$ (6,327)		$ (303)		$ (10,992)