Summary of Significant Accounting Policies, Reclassifications (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Reclassifications [Abstract]
Accounts receivable	$ (15,798)	$ (16,156)	$ 8,310
Accounts payable	(1,137)	8,167	18,593
Retainage payable	(2,481)	(27)	(13,011)
Net cash provided by operating activities	308,020	215,173	141,452
Additions to property, plant, and equipment	(195,882)	(305,157)	(256,558)
Net cash used in investing activities	(101,675)	(306,905)	(183,449)
Net increase in cash and cash equivalents	(97,552)	45,935	47,710
Cash and cash equivalents at beginning of period	191,128	145,193	97,483
Cash and cash equivalents at end of period	93,576	191,128	145,193
Accrued additions to property, plant, and equipment	17,525	6,032	11,396
Cash Flows Related To Accruals for Property, Plant and Equipment [Member]
Reclassifications [Abstract]
Accounts receivable		(16,156)	8,310
Accounts payable		8,167	18,593
Retainage payable		(27)	(13,011)
Net cash provided by operating activities		215,173	141,452
Additions to property, plant, and equipment		(305,157)	(256,558)
Net cash used in investing activities		(306,905)	(183,449)
Net increase in cash and cash equivalents		45,935	47,710
Cash and cash equivalents at beginning of period		145,193	97,483
Cash and cash equivalents at end of period		191,128	145,193
Accrued additions to property, plant, and equipment		6,032	11,396
Cash Flows Related To Accruals for Property, Plant and Equipment [Member] | As Reported [Member]
Reclassifications [Abstract]
Accounts receivable		(35,156)	8,310
Accounts payable		3,459	11,231
Retainage payable		1,913	(11,921)
Net cash provided by operating activities		193,405	135,179
Additions to property, plant, and equipment		(283,389)	(250,286)
Net cash used in investing activities		(285,137)	(177,176)
Net increase in cash and cash equivalents		45,935	47,710
Cash and cash equivalents at beginning of period		145,193	97,483
Cash and cash equivalents at end of period		191,128	145,193
Accrued additions to property, plant, and equipment		17,765	3,069
Cleco Power [Member]
Reclassifications [Abstract]
Accounts receivable	(14,858)	(16,261)	9,646
Accounts payable	(2,017)	8,934	18,254
Retainage payable	(2,481)	(27)	(13,011)
Net cash provided by operating activities	249,717	170,759	148,059
Additions to property, plant, and equipment	(182,574)	(149,211)	(255,585)
Net cash used in investing activities	(170,193)	(134,672)	(148,331)
Net increase in cash and cash equivalents	(117,454)	46,799	46,571
Cash and cash equivalents at beginning of period	184,912	138,113	91,542
Cash and cash equivalents at end of period	67,458	184,912	138,113
Accrued additions to property, plant, and equipment	21,007	5,697	11,335
Cleco Power [Member] | Cash Flows Related To Accruals for Property, Plant and Equipment [Member]
Reclassifications [Abstract]
Accounts receivable		(16,261)	9,646
Accounts payable		8,934	18,254
Retainage payable		(27)	(13,011)
Net cash provided by operating activities		170,759	148,059
Additions to property, plant, and equipment		(149,211)	(255,585)
Net cash used in investing activities		(134,672)	(148,331)
Net increase in cash and cash equivalents		46,799	46,571
Cash and cash equivalents at beginning of period		138,113	91,542
Cash and cash equivalents at end of period		184,912	138,113
Accrued additions to property, plant, and equipment		5,697	11,335
Cleco Power [Member] | Cash Flows Related To Accruals for Property, Plant and Equipment [Member] | As Reported [Member]
Reclassifications [Abstract]
Accounts receivable		(35,261)	9,646
Accounts payable		3,936	10,831
Retainage payable		1,913	(11,921)
Net cash provided by operating activities		148,701	141,726
Additions to property, plant, and equipment		(127,153)	(249,252)
Net cash used in investing activities		(112,614)	(141,998)
Net increase in cash and cash equivalents		46,799	46,571
Cash and cash equivalents at beginning of period		138,113	91,542
Cash and cash equivalents at end of period		184,912	138,113
Accrued additions to property, plant, and equipment		$ 17,765	$ 3,069