Disclosures about Segments (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Segment Reporting Information [Line Items]
Electric operations	$ 260,485	$ 261,101	$ 498,953	$ 513,899
Tolling operations	4,222	4,399	7,003	11,863
Other operations	12,983	10,245	25,711	21,119
Electric customer credits	(4,822)	0	(5,256)	0
Affiliate revenue	55	158	202	1,307
Operating revenue	272,923	275,903	526,613	548,188
Depreciation	29,985	29,798	59,084	54,051
Interest charges	25,619	24,518	52,232	46,952
Interest income	170	80	285	242
Equity income (loss) from investees, before tax	61,440	(1,129)	62,052	36,718
Gain on toll settlement			0	148,402
Federal and state income tax expense (benefit)	36,520	17,389	48,714	97,256
Segment profit (loss)	70,348	35,186	99,363	185,155
Additions to long-lived assets	35,918	33,062	77,713	363,855
Equity investment in investees	13,083		13,083		86,732
Total segment assets	4,058,719		4,058,719		4,161,410
Reconciliation of segment profit to consolidated profit:
Segment profit (loss)	70,348	35,186	99,363	185,155
Unallocated items:
Preferred dividends requirements, net of tax	15	12	26	23
Preferred stock redemption costs, net of tax	112	0	112	0
Net income applicable to common stock	70,221	35,174	99,225	185,132
Cleco Power [Member]
Segment Reporting Information [Line Items]
Electric operations	260,485	261,101	498,953	513,899
Tolling operations	0	0
Other operations	12,453	9,755	24,696	20,140
Electric customer credits	(4,822)		(5,256)
Affiliate revenue	348	344	694	686
Operating revenue	268,464	271,200	519,087	534,725
Depreciation	28,282	28,162	55,683	50,808
Interest charges	24,322	22,318	48,723	41,060
Interest income	168	76	281	234
Equity income (loss) from investees, before tax	0
Federal and state income tax expense (benefit)	15,879	19,236	30,279	31,731
Segment profit (loss)	35,694	39,089	65,724	71,249
Additions to long-lived assets	35,185	32,438	75,914	361,993
Equity investment in investees	13,073		13,073		13,073
Total segment assets	3,779,401		3,779,401		3,795,205
Reconciliation of segment profit to consolidated profit:
Segment profit (loss)	35,694	39,089	65,724	71,249
Midstream [Member]
Segment Reporting Information [Line Items]
Tolling operations	4,222	4,399	7,003	11,863
Other operations	7	1	7	1
Affiliate revenue	12	13	45	918
Operating revenue	4,241	4,413	7,055	12,782
Depreciation	1,457	1,444	2,913	2,887
Interest charges	628	1,431	1,211	4,863
Interest income			1
Equity income (loss) from investees, before tax	61,440	(1,129)	62,053	36,717
Gain on toll settlement				148,402
Federal and state income tax expense (benefit)	21,536	(1,241)	20,853	70,147
Segment profit (loss)	34,425	(1,991)	33,328	112,020
Additions to long-lived assets	122	574	1,128	1,122
Equity investment in investees					73,648
Total segment assets	233,099		233,099		316,165
Reconciliation of segment profit to consolidated profit:
Segment profit (loss)	34,425	(1,991)	33,328	112,020
Reconciling Items [Member]
Segment Reporting Information [Line Items]
Other operations	526	492	1,010	983
Affiliate revenue	13,075	12,011	24,096	23,494
Operating revenue	13,601	12,503	25,106	24,477
Depreciation	246	192	487	356
Interest charges	631	780	2,198	1,626
Interest income	(35)	14	(96)	605
Equity income (loss) from investees, before tax			(1)	1
Federal and state income tax expense (benefit)	(895)	(606)	(2,417)	(4,622)
Segment profit (loss)	229	(1,913)	311	1,887
Additions to long-lived assets	611	50	671	740
Equity investment in investees	10		10		11
Total segment assets	225,981		225,981		401,663
Reconciliation of segment profit to consolidated profit:
Segment profit (loss)	229	(1,913)	311	1,887
Eliminations [Member]
Segment Reporting Information [Line Items]
Other operations	(3)	(3)	(2)	(5)
Affiliate revenue	(13,380)	(12,210)	(24,633)	(23,791)
Operating revenue	(13,383)	(12,213)	(24,635)	(23,796)
Depreciation			1
Interest charges	38	(11)	100	(597)
Interest income	37	(10)	99	(597)
Federal and state income tax expense (benefit)			(1)
Segment profit (loss)		1		(1)
Total segment assets	(179,762)		(179,762)		(351,623)
Reconciliation of segment profit to consolidated profit:
Segment profit (loss)		$ 1		$ (1)