Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Effective Income Tax Rate [Line Items]
Effective income tax rate (in hundredths)	27.30%	37.80%	30.80%	35.20%
Capital Loss Carryforwards [Line Items]
Deferred tax asset					$ 2,700,000
Valuation allowance					1,200,000
Reversal of valuation allowance			1,200,000
Uncertain Tax Positions [Abstract]
Interest associated with uncertain tax positions	43,972,000		43,972,000		41,018,000
Interest expense related to uncertain tax positions	93,000	2,518,000	2,954,000	6,504,000
Liability for unrecognized tax benefits [Roll Forward]
Balance at Period Start			102,785,000
Reduction for tax positions of current period			3,116,000
Additions for tax positions of prior periods			10,585,000
Reduction for tax positions of prior periods			9,546,000
Balance at Period End	100,708,000		100,708,000		102,785,000
Deposits with the IRS			8,200,000		52,200,000
Maximum increase (decrease) in unrecognized tax benefits as a result of settlement with the IRS	(42,700,000)		(42,700,000)
Amounts deposited with the IRS - accrued income taxes payable					45,900,000
Amounts deposited with the IRS- accrued interest payable					6,300,000
Cleco Power [Member]
Effective Income Tax Rate [Line Items]
Effective income tax rate (in hundredths)	37.00%	33.70%	34.10%	32.10%
Uncertain Tax Positions [Abstract]
Interest associated with uncertain tax positions	16,567,000		16,567,000		15,211,000
Interest expense related to uncertain tax positions	(420,000)	(5,091,000)	1,356,000	(2,613,000)
Liability for unrecognized tax benefits [Roll Forward]
Balance at Period Start			60,975,000
Reduction for tax positions of current period			3,032,000
Additions for tax positions of prior periods			3,634,000
Reduction for tax positions of prior periods			8,670,000
Balance at Period End	52,907,000		52,907,000
Maximum increase (decrease) in unrecognized tax benefits as a result of settlement with the IRS	(2,600,000)		(2,600,000)
Cleco Power [Member] | Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	48,200,000		48,200,000
Net operating loss carryforwards, expiration date			2031
Cleco Power [Member] | State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	41,400,000		41,400,000
Net operating loss carryforwards, expiration date			2026
Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	51,700,000		51,700,000
Net operating loss carryforwards, expiration date			2031
State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 45,200,000		$ 45,200,000
Net operating loss carryforwards, expiration date			2026