Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees (Details) (USD $)	9 Months Ended		12 Months Ended			9 Months Ended							9 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2011 Discrimination Complaint [Member]	Dec. 31, 2010 Discrimination Complaint [Member]	Sep. 30, 2011 City of Opelousas Litigation [Member]	Sep. 30, 2011 Other Litigation Matters [Member]	Sep. 30, 2011 Madison Unit 3 Commitments [Member]	Sep. 30, 2011 Cleco Corporation [Member] Guarantee Issued to Entergy Louisiana and Entergy Gulf States for Performance Obligations of Perryville [Member]	Sep. 30, 2011 Cleco Corporation [Member] Guarantee Issued to Entergy Mississippi on behalf of Attala [Member]	Sep. 30, 2011 Cleco Corporation [Member] Guarantee Issued to Cleco Power on behalf of Acadia [Member]	Sep. 30, 2011 Cleco Corporation [Member] Guarantee Issued to Entergy Louisiana on behalf of Acadia [Member]	Sep. 30, 2011 Cleco Power [Member] Obligations Under Standby Letter of Credit Issued to the Louisiana Department of Labor [Member]	Sep. 30, 2011 Cleco Power [Member] Lignite Mining Agreement Guarantee [Member]	Sep. 30, 2011 APH [Member] Acadia Unit 1 Transaction [Member]	Sep. 30, 2011 APH [Member] Acadia Unit 2 Transaction [Member]	Sep. 30, 2011 Acadia Power Partners [Member] Acadia Unit 1 Transaction [Member]	Sep. 30, 2011 Acadia Power Partners [Member] Acadia Unit 1 Transaction [Member]
Loss Contingencies [Line Items]
Number of current employees who filed complaint		8
Number of former employees who filed complaint		4
Minimum amount sought by plaintiffs		$ 35,000,000				$ 32,000,000
Minimum amount sought by additional plaintiff		2,500,000
Number of claims settled and dismissed		1
Number of pending claims		12		252
Settlement agreement with charging party	1
Threshold of claims exceeded as a result of demand for arbitration						1,000,000
Associated payment demanded upon excess of claims threshold						19,000,000
Range of possible loss, maximum					6,000,000	32,500,000
Range of possible loss, minimum					2,000,000	4,000,000
Fuel Expenses Included in Audit	3,200,000,000
Risks and uncertainties [Abstract]
Letter of credit required if senior unsecured credit rating is not maintained						20,000,000
Additional letter of credit required in the event of further downgrade						15,000,000
Settlement amount with charging party			100,000			32,500,000
Guarantor Obligations [Line Items]
Face amount	4,225,000						42,400,000	500,000		10,000,000	3,725,000
Net amount	4,225,000						42,400,000	500,000			3,725,000
Liability recognized on the balance sheets	33,449,000						200,000					3,800,000	6,800,000	10,900,000
Percentage of ownership by affiliate (in hundredths)															100.00%	100.00%
Percentage of average losses on which letter of credit is based (in hundredths)											110.00%
Period (in years) over which average losses are determined											3Y
Fair value of indemnification liability recorded													13,500,000	21,800,000
Percentage of affiliate's indemnification liability accepted by entity (in hundredths)													50.00%	50.00%
Indemnification received from third parties													6,800,000	10,900,000
Term of indemnification obligation													3Y	3Y
Maximum residual value of indemnification obligation													0	200,000
Indemnification liability representing risk of payment													7,600,000	21,800,000
Income from contractual expiration of indemnification													500,000		1,000,000	1,100,000
Estimated maximum projected payment									10,000,000	298,800,000		72,500,000			30,000,000	30,000,000
Off-balance sheet commitments, expected termination dates [Abstract]
NET AMOUNT COMMITTED	4,225,000						42,400,000	500,000			3,725,000
LESS THAN ONE YEAR	3,725,000
MORE THAN 5 YEARS	500,000
On-balance sheet guarantees, expected termination dates [Abstract]
NET AMOUNT COMMITTED	33,449,000						200,000					3,800,000	6,800,000	10,900,000
1-3 YEARS	29,443,000
MORE THAN 5 YEARS	4,006,000
Total off-balance sheet commitments and on-balance sheet guarantees, expected termination dates [Abstract]
Total NET AMOUNT COMMITTED	37,674,000
Total LESS THAN ONE YEAR	3,725,000
Total 1-3 YEARS	29,443,000
Total MORE THAN 5 YEARS	4,506,000
New Markets Tax Credits [Abstract]
Equity contributions to be made to the fund	286,300,000
Net tax benefits and cash to be received from the fund	304,600,000
Excess net tax benefits to be received from the fund	18,300,000
Future equity contributions [Abstract]
Future equity contributions - 2011	11,508,000
Future equity contributions - 2012	76,629,000
Future equity contributions - 2013	36,225,000
Future equity contributions - 2014	22,927,000
Future equity contributions - 2015	21,904,000
Future equity contributions - Thereafter	20,808,000
Future equity contributions - Total	190,001,000
Due to be paid within the next twelve months	69,600,000
Tax benefits in excess of capital contributions	78,000,000
Tax benefits not utilized	63,600,000
Equity investments, imputed interest rate 6% [Abstract]
Principal payment schedule above:	190,001,000
Less: unamortized discount	22,098,000
Total	$ 167,903,000
Imputed interest rate (in hundredths)	6.00%
Period of recognition of gross investment amortization expense (in years)	10Y