Fair Value Accounting (Details) (USD $)	6 Months Ended																						3 Months Ended	6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2011 Cleco Power [Member]	Dec. 31, 2010 Cleco Power [Member]	Jun. 30, 2011 Cleco Power [Member] Carrying Value [Member]	Dec. 31, 2010 Cleco Power [Member] Carrying Value [Member]	Jun. 30, 2011 Cleco Power [Member] Estimated Fair Value [Member]	Dec. 31, 2010 Cleco Power [Member] Estimated Fair Value [Member]	Jun. 30, 2011 Cleco Power [Member] Measured on a Recurring Basis [Member] Estimated Fair Value [Member]	Dec. 31, 2010 Cleco Power [Member] Measured on a Recurring Basis [Member] Estimated Fair Value [Member]	Jun. 30, 2011 Cleco Power [Member] Measured on a Recurring Basis [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	Dec. 31, 2010 Cleco Power [Member] Measured on a Recurring Basis [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	Jun. 30, 2011 Cleco Power [Member] Measured on a Recurring Basis [Member] Significant Other Observable Inputs (Level 2) [Member]	Dec. 31, 2010 Cleco Power [Member] Measured on a Recurring Basis [Member] Significant Other Observable Inputs (Level 2) [Member]	Jun. 30, 2011 Cleco Power [Member] Maximum Amount of Loss [Member]	Jun. 30, 2011 Carrying Value [Member]	Dec. 31, 2010 Carrying Value [Member]	Jun. 30, 2011 Estimated Fair Value [Member]	Dec. 31, 2010 Estimated Fair Value [Member]	Jun. 30, 2011 Measured on a Recurring Basis [Member] Estimated Fair Value [Member]	Dec. 31, 2010 Measured on a Recurring Basis [Member] Estimated Fair Value [Member]	Jun. 30, 2011 Maximum Amount of Loss [Member]	Jun. 30, 2010 Swap [Member]	Jun. 30, 2011 Swap [Member]	Jun. 30, 2010 Swap [Member]	Jun. 30, 2011 Measured on a Recurring Basis [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	Dec. 31, 2010 Measured on a Recurring Basis [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	Jun. 30, 2011 Measured on a Recurring Basis [Member] Significant Other Observable Inputs (Level 2) [Member]	Dec. 31, 2010 Measured on a Recurring Basis [Member] Significant Other Observable Inputs (Level 2) [Member]	Jun. 30, 2011 Derivatives Not Designated As Hedging Instruments [Member] Fuel Cost Hedges [Member]	Dec. 31, 2010 Derivatives Not Designated As Hedging Instruments [Member] Fuel Cost Hedges [Member]	Jun. 30, 2011 Derivatives Not Designated As Hedging Instruments [Member] Fuel Cost Hedges [Member] Risk Management Liability, Net [Member]	Dec. 31, 2010 Derivatives Not Designated As Hedging Instruments [Member] Fuel Cost Hedges [Member] Risk Management Liability, Net [Member]	Jun. 30, 2011 Derivatives Not Designated As Hedging Instruments [Member] Fuel Cost Hedges [Member] Other Deferred Credits [Member]	Dec. 31, 2010 Derivatives Not Designated As Hedging Instruments [Member] Fuel Cost Hedges [Member] Other Deferred Credits [Member]
Financial instruments not marked-to-market
Cash and cash equivalents					$ 149,841,000	$ 184,912,000	$ 149,841,000	$ 184,912,000								$ 162,126,000	$ 191,128,000	$ 162,126,000	$ 191,128,000
Restricted cash					35,103,000	40,951,000	35,103,000	40,951,000								35,199,000	41,048,000	35,199,000	41,048,000
Long-term debt, excluding debt issuance costs					1,382,553,000	1,388,836,000	1,486,438,000	1,447,063,000								1,392,553,000	1,403,836,000	1,496,438,000	1,462,063,000
Preferred stock not subject to mandatory redemption																	1,029,000		844,000
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentrations of credit risk through short-term investments															180,800,000							192,600,000
Concentrations of credit risk through short-term investments in cash															145,700,000							157,400,000
Concentrations of credit risk through short-term investments in restricted cash															35,100,000							35,200,000
Established guidelines for short-term investments to mitigate potential credit risk [Abstract]
Minimum assets under management in money market funds	1,000,000,000
Minimum existence of investments (in years)	not less than two years
Maximum portfolios composition securities issued by foreign entities (in hundredths)	50.00%
Interest rate cash flow hedge [Abstract]
Amount of hedged item																								50,000,000
Description of hedged item																								bank loan with variable interest, paid monthly, and calculated at 3.00% plus the one-month LIBOR
Underlying risk																								risk of future floating interest rates
Fixed interest rate (in hundredths)																								1.84%
Net interest expense recognized on hedged item (in hundredths)																								4.84%
Reclassification adjustments of interest rate cash flow hedge																							200,000		400,000
Asset Description
Energy market derivatives										97,000				97,000							97,000								97,000
Institutional money market funds									180,802,000	224,451,000			180,802,000	224,451,000						192,599,000	229,748,000							192,599,000	229,748,000
Total assets									180,802,000	224,548,000			180,802,000	224,548,000						192,599,000	229,845,000							192,599,000	229,845,000
Liability Description
Energy market derivatives									7,665,000	15,245,000	1,532,000	3,317,000	6,133,000	11,928,000						7,665,000	15,245,000					1,532,000	3,317,000	6,133,000	11,928,000
Total liabilities									7,665,000	15,245,000	1,532,000	3,317,000	6,133,000	11,928,000						7,665,000	15,245,000					1,532,000	3,317,000	6,133,000	11,928,000
Net current risk management liability	5,743,000	9,027,000	5,743,000	9,027,000
Current derivative positions	7,600,000
Non-current liability derivative positions	100,000
Current margin deposits	1,800,000	4,300,000
Option premiums	0
Institutional money market funds cash and cash equivalents	157,400,000		145,700,000
Institutional money market funds current restricted cash	8,100,000		8,100,000
Institutional money market funds non-current restricted cash	27,100,000		27,000,000
Fair values of derivative instruments [Abstract]
Current																																(7,576,000)	(13,497,000)
Long-term																																		(89,000)	(1,651,000)
Total																														$ (7,665,000)	$ (15,148,000)