Fair Value Accounting, Fair Value Measurements and Disclosures(Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Cash and Cash Equivalents [Member]
Asset Description
Institutional money market funds	$ 37,300
Restricted Cash and Cash Equivalents, Current [Member]
Asset Description
Institutional money market funds	3,400
Restricted Cash and Cash Equivalents, Noncurrent [Member]
Asset Description
Institutional money market funds	5,100
Restricted Investment, Noncurrent [Member]
Asset Description
Institutional money market funds	2,100
Municipal Bonds [Member] | Restricted Investment, Noncurrent [Member]
Asset Description
Available-for-sale Securities, Debt Securities	9,600
Corporate Bond Securities [Member] | Restricted Investment, Noncurrent [Member]
Asset Description
Available-for-sale Securities, Debt Securities	500
Measured On A Recurring Basis [Member] | Estimated Fair Value [Member]
Asset Description
Institutional money market funds	47,901	39,489
Total Assets	58,045	49,692
Liability Description
Interest rate derivatives	0	2,627
Long-term debt	1,419,560	1,579,674
Total Liabilities	1,419,560	1,582,301
Measured On A Recurring Basis [Member] | Estimated Fair Value [Member] | Municipal Bonds [Member]
Asset Description
Available-for-sale Securities, Debt Securities	9,631	10,203
Measured On A Recurring Basis [Member] | Estimated Fair Value [Member] | Corporate Bond Securities [Member]
Asset Description
Available-for-sale Securities, Debt Securities	513	0
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
Interest rate derivatives	0	0
Long-term debt	0	0
Total Liabilities	0	0
Measured On A Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Municipal Bonds [Member]
Asset Description
Available-for-sale Securities, Debt Securities	0	0
Measured On A Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Corporate Bond Securities [Member]
Asset Description
Available-for-sale Securities, Debt Securities	0	0
Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member]
Asset Description
Institutional money market funds	47,901	39,489
Total Assets	58,045	49,692
Liability Description
Interest rate derivatives	0	2,627
Long-term debt	1,419,560	1,579,674
Total Liabilities	1,419,560	1,582,301
Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Municipal Bonds [Member]
Asset Description
Available-for-sale Securities, Debt Securities	9,631	10,203
Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate Bond Securities [Member]
Asset Description
Available-for-sale Securities, Debt Securities	513	0
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
Interest rate derivatives	0	0
Long-term debt	0	0
Total Liabilities	0	0
Measured On A Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Municipal Bonds [Member]
Asset Description
Available-for-sale Securities, Debt Securities	0	0
Measured On A Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Corporate Bond Securities [Member]
Asset Description
Available-for-sale Securities, Debt Securities	0	0
Cleco Power [Member] | Cash and Cash Equivalents [Member]
Asset Description
Institutional money market funds	33,500
Cleco Power [Member] | Restricted Cash and Cash Equivalents, Current [Member]
Asset Description
Institutional money market funds	3,400
Cleco Power [Member] | Restricted Cash and Cash Equivalents, Noncurrent [Member]
Asset Description
Institutional money market funds	5,000
Cleco Power [Member] | Restricted Investment, Noncurrent [Member]
Asset Description
Institutional money market funds	2,100
Cleco Power [Member] | Municipal Bonds [Member]
Asset Description
Available-for-sale Securities, Debt Securities	9,631	10,203
Cleco Power [Member] | Municipal Bonds [Member] | Restricted Investment, Noncurrent [Member]
Asset Description
Available-for-sale Securities, Debt Securities	9,600
Cleco Power [Member] | Corporate Bond Securities [Member]
Asset Description
Available-for-sale Securities, Debt Securities	513	0
Cleco Power [Member] | Corporate Bond Securities [Member] | Restricted Investment, Noncurrent [Member]
Asset Description
Available-for-sale Securities, Debt Securities	500
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Estimated Fair Value [Member]
Asset Description
Institutional money market funds	44,005	33,292
Total Assets	54,149	43,495
Liability Description
Interest rate derivatives	0	2,627
Long-term debt	1,419,560	1,554,674
Total Liabilities	1,419,560	1,557,301
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Estimated Fair Value [Member] | Municipal Bonds [Member]
Asset Description
Available-for-sale Securities, Debt Securities	9,631	10,203
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Estimated Fair Value [Member] | Corporate Bond Securities [Member]
Asset Description
Available-for-sale Securities, Debt Securities	513	0
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
Interest rate derivatives	0	0
Long-term debt	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] | Municipal Bonds [Member]
Asset Description
Available-for-sale Securities, Debt Securities	0	0
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Corporate Bond Securities [Member]
Asset Description
Available-for-sale Securities, Debt Securities	0	0
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member]
Asset Description
Institutional money market funds	44,005	33,292
Total Assets	54,149	43,495
Liability Description
Interest rate derivatives	0	2,627
Long-term debt	1,419,560	1,554,674
Total Liabilities	1,419,560	1,557,301
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Municipal Bonds [Member]
Asset Description
Available-for-sale Securities, Debt Securities	9,631	10,203
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate Bond Securities [Member]
Asset Description
Available-for-sale Securities, Debt Securities	513	0
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
Interest rate derivatives	0	0
Long-term debt	0	0
Total Liabilities	0	0
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Municipal Bonds [Member]
Asset Description
Available-for-sale Securities, Debt Securities	0	0
Cleco Power [Member] | Measured On A Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Corporate Bond Securities [Member]
Asset Description
Available-for-sale Securities, Debt Securities	$ 0	$ 0