Disclosures about Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012 entity	Sep. 30, 2011	Sep. 30, 2012 entity	Sep. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Number of transmission interconnection facility subsidiaries	2		2
Revenue
Electric operations	$ 282,894	$ 324,532	$ 720,776	$ 823,484
Tolling operations	0	9,133	0	16,137
Other operations	15,408	16,064	38,464	41,775
Electric customer credits	(930)	1,852	1,025	(3,405)
Affiliate revenue	0	0	0	202
Operating revenue, net	297,372	351,581	760,265	878,193
Depreciation	34,931	31,237	99,028	91,749
Interest charges	21,966	25,779	63,205	78,011
Interest income	132	509	163	794
Equity income (loss) from investees, before tax	0	(1)	1	62,051
Federal and state income tax expense	20,179	24,737	54,110	73,451
Net income	63,818	65,842	140,536	165,205
Additions to long-lived assets	66,375	80,368	168,018	158,033
Equity investment in investees	14,541		14,541		14,540
Total segment assets	4,106,893		4,106,893		4,050,202
Unallocated items:
Preferred dividends requirements			0	26
Preferred stock redemption costs			0	112
Net income applicable to common stock	63,818	65,842	140,536	165,067
Midstream [Member]
Revenue
Electric operations	0	0	0	0
Tolling operations	13,890	9,133	21,434	16,137
Other operations	1	1	2	8
Electric customer credits	0	0	0	0
Affiliate revenue	0	0	0	45
Operating revenue, net	13,891	9,134	21,436	16,190
Depreciation	1,499	1,457	4,491	4,370
Interest charges	(69)	752	244	1,963
Interest income	0	5	0	6
Equity income (loss) from investees, before tax		0	0	62,053
Federal and state income tax expense	2,489	444	7,278	21,296
Net income	3,429	5,946	11,053	39,274
Additions to long-lived assets	799	4,074	6,811	5,202
Equity investment in investees	0		0		0
Total segment assets	221,503		221,503		233,891
Reconciling Items [Member]
Revenue
Electric operations	0	0	0	0
Tolling operations	0	0	0	0
Other operations	502	500	1,496	1,511
Electric customer credits	0	0	0	0
Affiliate revenue	12,343	13,448	37,540	37,544
Operating revenue, net	12,845	13,948	39,036	39,055
Depreciation	233	241	689	728
Interest charges	(124)	(308)	1,320	1,891
Interest income	(194)	199	(379)	103
Equity income (loss) from investees, before tax		(1)	1	(2)
Federal and state income tax expense	(2,050)	(7,363)	(7,916)	(9,781)
Net income	2,606	6,063	7,610	6,374
Additions to long-lived assets	503	81	1,371	749
Equity investment in investees	9		9		8
Total segment assets	194,996		194,996		201,074
Eliminations [Member]
Revenue
Electric operations	0	0	0	0
Tolling operations	(13,890)	0	(21,434)	0
Other operations	0	(2)	(1)	(5)
Electric customer credits	0	0	0	0
Affiliate revenue	(12,686)	(13,795)	(38,570)	(38,428)
Operating revenue, net	(26,576)	(13,797)	(60,005)	(38,433)
Depreciation	0	0	1	1
Interest charges	197	29	388	128
Interest income	197	29	389	128
Equity income (loss) from investees, before tax		0	0	0
Federal and state income tax expense	0	0	0	1
Net income	0	0	0	0
Additions to long-lived assets	0	0	0	0
Equity investment in investees	0		0		0
Total segment assets	(149,737)		(149,737)		(111,234)
Unallocated Amount to Segment [Member]
Unallocated items:
Preferred dividends requirements				26
Preferred stock redemption costs				112
Cleco Power [Member]
Revenue
Electric operations	282,894	324,532	720,776	823,484
Tolling operations	0	0	0	0
Other operations	14,905	15,565	36,967	40,261
Electric customer credits	(930)	1,852	1,025	(3,405)
Affiliate revenue	343	347	1,030	1,041
Operating revenue, net	297,212	342,296	759,798	861,381
Depreciation	33,199	29,539	93,847	86,650
Interest charges	21,962	25,306	61,253	74,029
Interest income	129	276	153	557
Equity income (loss) from investees, before tax		0	0	0
Federal and state income tax expense	19,740	31,656	54,748	61,935
Net income	57,783	53,833	121,873	119,557
Additions to long-lived assets	65,073	76,213	159,836	152,082
Equity investment in investees	14,532		14,532		14,532
Total segment assets	$ 3,840,131		$ 3,840,131		$ 3,726,471