Disclosures about Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 entity	Mar. 31, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Number of transmission interconnection facility subsidiaries	2
Revenue
Electric operations	$ 229,425	$ 209,590
Tolling operations	0	0
Other operations	11,543	10,946
Electric customer credits	(21)	2,237
Affiliate revenue	0	0
Operating revenue, net	240,947	222,773
Depreciation	34,032	31,846
Interest charges	21,456	20,624
Interest income	201	34
Equity income (loss) from investees, before tax	0	1
Federal and state income tax expense (benefit)	13,081	13,410
Net income (loss)	27,133	30,031
Additions to long-lived assets	43,948	39,351
Equity investment in investees	14,541		14,540
Total segment assets	4,067,132		4,147,349
Midstream [Member]
Revenue
Electric operations	0	0
Tolling operations	4,837	1,234
Other operations	1	1
Electric customer credits	0	0
Affiliate revenue	0	0
Operating revenue, net	4,838	1,235
Depreciation	1,500	1,532
Interest charges	(239)	1,471
Interest income	0	0
Equity income (loss) from investees, before tax		0
Federal and state income tax expense (benefit)	(840)	739
Net income (loss)	(1,334)	1,090
Additions to long-lived assets	1,829	(13)
Equity investment in investees	0		0
Total segment assets	212,889		215,342
All Other Segments [Member]
Revenue
Electric operations	0	0
Tolling operations	0	0
Other operations	504	497
Electric customer credits	0	0
Affiliate revenue	11,925	11,607
Operating revenue, net	12,429	12,104
Depreciation	203	224
Interest charges	163	619
Interest income	(180)	(44)
Equity income (loss) from investees, before tax		1
Federal and state income tax expense (benefit)	(317)	(1,835)
Net income (loss)	674	2,136
Additions to long-lived assets	561	387
Equity investment in investees	8		8
Total segment assets	174,057		201,678
Eliminations [Member]
Revenue
Electric operations	0	0
Tolling operations	(4,837)	(1,234)
Other operations	0	0
Electric customer credits	0	0
Affiliate revenue	(12,261)	(11,952)
Operating revenue, net	(17,098)	(13,186)
Depreciation	(1)	0
Interest charges	183	48
Interest income	183	48
Equity income (loss) from investees, before tax		0
Federal and state income tax expense (benefit)	0	(1)
Net income (loss)	0	0
Additions to long-lived assets	0	0
Equity investment in investees	1		0
Total segment assets	(146,917)		(141,400)
Cleco Power [Member]
Revenue
Electric operations	229,425	209,590
Tolling operations	0	0
Other operations	11,038	10,448
Electric customer credits	(21)	2,237
Affiliate revenue	336	345
Operating revenue, net	240,778	222,620
Depreciation	32,330	30,090
Interest charges	21,349	18,486
Interest income	198	30
Equity income (loss) from investees, before tax		0
Federal and state income tax expense (benefit)	14,238	14,507
Net income (loss)	27,793	26,805
Additions to long-lived assets	41,558	38,977
Equity investment in investees	14,532		14,532
Total segment assets	$ 3,827,103		$ 3,871,729