Fair Value Accounting, Fair Value of Financial Assets and Liabilities Measured on a Recurring Basis (Details) (USD $)	Mar. 31, 2012	Dec. 31, 2011
Liability Description
Institutional money market funds cash and cash equivalents	$ 39,800,000
Institutional money market funds current restricted cash	3,300,000
Institutional money market funds non-current restricted cash	27,300,000
Energy Market Derivatives [Member]
Liability Description
Net current liability	3,100,000
Option premiums	200,000
Measured On A Recurring Basis [Member] | Estimated Fair Value [Member]
Asset Description
Institutional money market funds	70,380,000	119,327,000
Total Assets	71,706,000	119,327,000
Liability Description
Long-term debt, excluding debt issuance costs	1,483,939,000	1,542,867,000
Total Liabilities	1,487,247,000	1,551,533,000
Measured On A Recurring Basis [Member] | Estimated Fair Value [Member] | Energy Market Derivatives [Member]
Liability Description
Derivative liabilities	3,308,000	5,336,000
Measured On A Recurring Basis [Member] | Estimated Fair Value [Member] | Interest Rate Derivatives [Member]
Asset Description
Derivative assets	1,326,000	0
Liability Description
Derivative liabilities	0	3,330,000
Measured On A Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Asset Description
Institutional money market funds	0	0
Total Assets	0	0
Liability Description
Long-term debt, excluding debt issuance costs	0	0
Total Liabilities	0	0
Measured On A Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Energy Market Derivatives [Member]
Liability Description
Derivative liabilities	0	0
Measured On A Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest Rate Derivatives [Member]
Asset Description
Derivative assets	0	0
Liability Description
Derivative liabilities	0	0
Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member]
Asset Description
Institutional money market funds	70,380,000	119,327,000
Total Assets	71,706,000	119,327,000
Liability Description
Long-term debt, excluding debt issuance costs	1,483,939,000	1,542,867,000
Total Liabilities	1,487,247,000	1,551,533,000
Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Energy Market Derivatives [Member]
Liability Description
Derivative liabilities	3,308,000	5,336,000
Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Derivatives [Member]
Asset Description
Derivative assets	1,326,000	0
Liability Description
Derivative liabilities	0	3,330,000
Measured On A Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member]
Asset Description
Institutional money market funds	0	0
Total Assets	0	0
Liability Description
Long-term debt, excluding debt issuance costs	0	0
Total Liabilities	0	0
Measured On A Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Energy Market Derivatives [Member]
Liability Description
Derivative liabilities	0	0
Measured On A Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Derivatives [Member]
Asset Description
Derivative assets	0	0
Liability Description
Derivative liabilities	0	0
Cleco Power [Member]
Liability Description
Institutional money market funds cash and cash equivalents	33,000,000
Institutional money market funds current restricted cash	3,300,000
Institutional money market funds non-current restricted cash	27,200,000
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Estimated Fair Value [Member]
Asset Description
Institutional money market funds	63,483,000	100,331,000
Total Assets	64,809,000	100,331,000
Liability Description
Long-term debt, excluding debt issuance costs	1,483,939,000	1,532,867,000
Total Liabilities	1,487,247,000	1,541,533,000
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Estimated Fair Value [Member] | Energy Market Derivatives [Member]
Liability Description
Derivative liabilities	3,308,000	5,336,000
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Estimated Fair Value [Member] | Interest Rate Derivatives [Member]
Asset Description
Derivative assets	1,326,000	0
Liability Description
Derivative liabilities	0	3,330,000
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Asset Description
Institutional money market funds	0	0
Total Assets	0	0
Liability Description
Long-term debt, excluding debt issuance costs	0	0
Total Liabilities	0	0
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Energy Market Derivatives [Member]
Liability Description
Derivative liabilities	0	0
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest Rate Derivatives [Member]
Asset Description
Derivative assets	0	0
Liability Description
Derivative liabilities	0	0
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member]
Asset Description
Institutional money market funds	63,483,000	100,331,000
Total Assets	64,809,000	100,331,000
Liability Description
Long-term debt, excluding debt issuance costs	1,483,939,000	1,532,867,000
Total Liabilities	1,487,247,000	1,541,533,000
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Energy Market Derivatives [Member]
Liability Description
Derivative liabilities	3,308,000	5,336,000
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Derivatives [Member]
Asset Description
Derivative assets	1,326,000	0
Liability Description
Derivative liabilities	0	3,330,000
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member]
Asset Description
Institutional money market funds	0	0
Total Assets	0	0
Liability Description
Long-term debt, excluding debt issuance costs	0	0
Total Liabilities	0	0
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Energy Market Derivatives [Member]
Liability Description
Derivative liabilities	0	0
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Derivatives [Member]
Asset Description
Derivative assets	0	0
Liability Description
Derivative liabilities	$ 0	$ 0