Disclosures about Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012 entity	Jun. 30, 2011	Jun. 30, 2012 entity	Jun. 30, 2011	Dec. 31, 2011
Revenue
Electric operations	$ 228,293	$ 260,485	$ 437,883	$ 498,953
Tolling operations	0	4,222	0	7,003
Other operations	12,111	12,983	23,056	25,711
Electric customer credits	(281)	(4,822)	1,955	(5,256)
Affiliate revenue	0	55	0	202
Operating revenue, net	240,123	272,923	462,894	526,613
Depreciation	32,250	30,699	64,097	60,512
Interest charges	20,616	25,619	41,240	52,232
Interest income	(3)	170	31	285
Equity income (loss) from investees, before tax	0	61,440	1	62,052
Federal and state income tax expense	20,520	36,520	33,930	48,714
Net income	46,686	70,348	76,718	99,363
Additions to long-lived assets	62,121	35,918	109,094	77,713
Equity investment in investees	14,541		14,541		14,540
Total segment assets	4,003,508		4,003,508		4,050,202
Reconciliation of segment profit to consolidated profit:
Number of transmission interconnection facility subsidiaries	2		2
Unallocated items:
Preferred dividends requirements	0	15	0	26
Preferred stock redemption costs	0	112	0	112
Net income applicable to common stock	46,686	70,221	76,718	99,225
Midstream [Member]
Revenue
Electric operations	0	0	0	0
Tolling operations	6,309	4,222	7,543	7,003
Other operations	1	7	1	7
Electric customer credits	0	0	0	0
Affiliate revenue	0	12	0	45
Operating revenue, net	6,310	4,241	7,544	7,055
Depreciation	1,460	1,457	2,992	2,913
Interest charges	(1,159)	628	313	1,211
Interest income	0	0	0	1
Equity income (loss) from investees, before tax		61,440	0	62,053
Federal and state income tax expense	4,051	21,536	4,789	20,853
Net income	6,534	34,425	7,624	33,328
Additions to long-lived assets	6,025	122	2,223	1,128
Equity investment in investees	0		0		0
Total segment assets	218,073		218,073		233,891
Reconciling Items [Member]
Revenue
Electric operations	0	0	0	0
Tolling operations	0	0	0	0
Other operations	497	526	994	1,010
Electric customer credits	0	0	0	0
Affiliate revenue	13,590	13,075	25,197	24,096
Operating revenue, net	14,087	13,601	26,191	25,106
Depreciation	232	246	456	487
Interest charges	824	631	1,444	2,198
Interest income	(141)	(35)	(185)	(96)
Equity income (loss) from investees, before tax		0	1	(1)
Federal and state income tax expense	(4,031)	(895)	(5,866)	(2,417)
Net income	2,868	229	5,004	311
Additions to long-lived assets	482	611	869	671
Equity investment in investees	9		9		8
Total segment assets	189,000		189,000		201,074
Eliminations [Member]
Revenue
Electric operations	0	0	0	0
Tolling operations	(6,309)	0	(7,543)	0
Other operations	0	(3)	(1)	(2)
Electric customer credits	0	0	0	0
Affiliate revenue	(13,932)	(13,380)	(25,884)	(24,633)
Operating revenue, net	(20,241)	(13,383)	(33,428)	(24,635)
Depreciation	(1)	0	1	1
Interest charges	146	38	192	100
Interest income	144	37	193	99
Equity income (loss) from investees, before tax		0	0	0
Federal and state income tax expense	(1)	0	(1)	(1)
Net income	0	0	1	0
Additions to long-lived assets	0	0	0	0
Equity investment in investees	0		0		0
Total segment assets	(108,351)		(108,351)		(111,234)
Unallocated Amount to Segment [Member]
Unallocated items:
Preferred dividends requirements		15		26
Preferred stock redemption costs		112		112
Cleco Power [Member]
Revenue
Electric operations	228,293	260,485	437,883	498,953
Tolling operations	0	0	0	0
Other operations	11,613	12,453	22,062	24,696
Electric customer credits	(281)	(4,822)	1,955	(5,256)
Affiliate revenue	342	348	687	694
Operating revenue, net	239,967	268,464	462,587	519,087
Depreciation	30,559	28,996	60,648	57,111
Interest charges	20,805	24,322	39,291	48,723
Interest income	(6)	168	23	281
Equity income (loss) from investees, before tax		0	0	0
Federal and state income tax expense	20,501	15,879	35,008	30,279
Net income	37,284	35,694	64,089	65,724
Additions to long-lived assets	55,614	35,185	106,002	75,914
Equity investment in investees	14,532		14,532		14,532
Total segment assets	$ 3,704,786		$ 3,704,786		$ 3,726,471