Summary of Significant Accounting Policies, Reclassifications (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Depreciation	$ 132,407	$ 122,578	$ 114,584
Reclassifications [Abstract]
Accounts receivable	(11,543)	(19,146)	(12,503)
Accounts payable	(23,016)	(3,618)	8,140
Other deferred accounts	15,695	(4,305)	114
Net cash provided by operating activities	263,105	310,061	216,899
Additions to property, plant, and equipment	(245,033)	(202,405)	(306,883)
Net cash used in investing activities	(229,164)	(103,716)	(308,631)
Net increase in cash and cash equivalents	(62,556)	(97,552)	45,935
Cash and cash equivalents at beginning of period	93,576	191,128	145,193
Cash and cash equivalents at end of period	31,020	93,576	191,128
Accrued additions to property, plant, and equipment	16,102	17,525	6,032
Cash Flows Related To Contributions Received In Aid Of Construction Adjustment [Member]
Reclassifications [Abstract]
Accounts receivable		(19,146)	(12,503)
Other deferred accounts		4,305	(114)
Net cash provided by operating activities		310,061	216,899
Additions to property, plant, and equipment		(202,405)	(306,883)
Net cash used in investing activities		(103,716)	(308,631)
Net increase in cash and cash equivalents		(97,552)	45,935
Cash and cash equivalents at beginning of period		191,128	145,193
Cash and cash equivalents at end of period		93,576	191,128
Cash Flows Related To Contributions Received In Aid Of Construction Adjustment [Member] | As Reported [Member]
Reclassifications [Abstract]
Accounts receivable		(15,798)	(16,156)
Other deferred accounts		(1,084)	1,813
Net cash provided by operating activities		308,020	215,173
Additions to property, plant, and equipment		(200,364)	(305,157)
Net cash used in investing activities		(101,675)	(306,905)
Net increase in cash and cash equivalents		(97,552)	45,935
Cash and cash equivalents at beginning of period		191,128	145,193
Cash and cash equivalents at end of period		93,576	191,128
Cleco Power [Member]
Depreciation	125,486	115,634	107,966
Reclassifications [Abstract]
Accounts receivable	(12,290)	(18,206)	(12,608)
Accounts payable	(22,874)	(4,498)	8,907
Other deferred accounts	19,989	2,399	10,009
Net cash provided by operating activities	244,100	251,758	172,485
Additions to property, plant, and equipment	(238,943)	(184,615)	(150,937)
Net cash used in investing activities	(203,557)	(172,234)	(136,398)
Net increase in cash and cash equivalents	(44,090)	(117,454)	46,799
Cash and cash equivalents at beginning of period	67,458	184,912	138,113
Cash and cash equivalents at end of period	23,368	67,458	184,912
Accrued additions to property, plant, and equipment	15,547	21,007	5,697
Cleco Power [Member] | Cash Flows Related To Contributions Received In Aid Of Construction Adjustment [Member]
Reclassifications [Abstract]
Accounts receivable		(18,206)	(12,608)
Other deferred accounts		(2,399)	(10,009)
Net cash provided by operating activities		251,758	172,485
Additions to property, plant, and equipment		(184,615)	(150,937)
Net cash used in investing activities		(172,234)	(136,398)
Net increase in cash and cash equivalents		(117,454)	46,799
Cash and cash equivalents at beginning of period		184,912	138,113
Cash and cash equivalents at end of period		67,458	184,912
Cleco Power [Member] | Cash Flows Related To Contributions Received In Aid Of Construction Adjustment [Member] | As Reported [Member]
Reclassifications [Abstract]
Accounts receivable		(14,858)	(16,261)
Other deferred accounts		(7,788)	(8,082)
Net cash provided by operating activities		249,717	170,759
Additions to property, plant, and equipment		(182,574)	(149,211)
Net cash used in investing activities		(170,193)	(134,672)
Net increase in cash and cash equivalents		(117,454)	46,799
Cash and cash equivalents at beginning of period		184,912	138,113
Cash and cash equivalents at end of period		67,458	184,912
ReclassificationOfPlantAcquisitionAdjustmentAmortization [Member]
Depreciation		$ 2,800	$ 2,400