Summary of Significant Accounting Policies Summary of Significant Accounting Policies, Reclassifications (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Increase (Decrease) in Accounts Receivable			$ (13,247)	$ (21,691)
Depreciation	34,931	31,237	99,028	91,749
Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net			(17,388)	2,181
Net Cash Provided by (Used in) Operating Activities, Continuing Operations			224,604	263,590
Payments to Acquire Property, Plant, and Equipment			(177,146)	(146,617)
Net Cash Provided by (Used in) Investing Activities			(149,218)	(55,045)
Cash and Cash Equivalents, Period Increase (Decrease)			(25,212)	(32,896)
Cash and Cash Equivalents, at Carrying Value	68,364	158,232	68,364	158,232	93,576	191,128
Cash Flows Related To Contributions Received In Aid Of Construction [Member]
Increase (Decrease) in Accounts Receivable				(21,691)
Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net				2,181
Net Cash Provided by (Used in) Operating Activities, Continuing Operations				263,590
Payments to Acquire Property, Plant, and Equipment				(146,617)
Net Cash Provided by (Used in) Investing Activities				(55,045)
Cash and Cash Equivalents, Period Increase (Decrease)				(32,896)
Cash and Cash Equivalents, at Carrying Value		158,232		158,232		191,128
Cash Flows Related To Contributions Received In Aid Of Construction [Member] | Scenario, Previously Reported [Member]
Increase (Decrease) in Accounts Receivable				(18,274)
Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net				(2,184)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations				262,642
Payments to Acquire Property, Plant, and Equipment				(145,669)
Net Cash Provided by (Used in) Investing Activities				(54,097)
Cash and Cash Equivalents, Period Increase (Decrease)				(32,896)
Cash and Cash Equivalents, at Carrying Value		158,232		158,232		191,128
Cleco Power [Member]
Increase (Decrease) in Accounts Receivable			(13,807)	(23,859)
Depreciation	33,199	29,539	93,847	86,650
Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net			(20,057)	(1,996)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations			205,527	185,636
Payments to Acquire Property, Plant, and Equipment			(173,268)	(131,962)
Net Cash Provided by (Used in) Investing Activities			(138,329)	(113,804)
Cash and Cash Equivalents, Period Increase (Decrease)			(16,880)	(41,897)
Cash and Cash Equivalents, at Carrying Value	50,578	143,015	50,578	143,015	67,458	184,912
Cleco Power [Member] | Cash Flows Related To Contributions Received In Aid Of Construction [Member]
Increase (Decrease) in Accounts Receivable				(23,859)
Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net				(1,996)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations				185,636
Payments to Acquire Property, Plant, and Equipment				(131,962)
Net Cash Provided by (Used in) Investing Activities				(113,804)
Cash and Cash Equivalents, Period Increase (Decrease)				(41,897)
Cash and Cash Equivalents, at Carrying Value		143,015		143,015		184,912
Cleco Power [Member] | Cash Flows Related To Contributions Received In Aid Of Construction [Member] | Scenario, Previously Reported [Member]
Increase (Decrease) in Accounts Receivable				(20,442)
Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net				(6,361)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations				184,688
Payments to Acquire Property, Plant, and Equipment				(131,014)
Net Cash Provided by (Used in) Investing Activities				(112,856)
Cash and Cash Equivalents, Period Increase (Decrease)				(41,897)
Cash and Cash Equivalents, at Carrying Value		143,015		143,015		184,912
Reclassification Of Plant Acquisition Adjustment Amortization [Member]
Depreciation		$ 700		$ 2,100