Disclosures about Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 entity	Mar. 31, 2011	Dec. 31, 2011
Revenue
Electric operations	$ 209,590	$ 238,468
Tolling operations	0	2,781
Other operations	10,946	12,728
Electric customer credits	2,237	(434)
Affiliate revenue	0	147
Operating revenue, net	222,773	253,690
Depreciation	31,167	29,098
Interest charges	20,624	26,614
Interest income	34	115
Equity income (loss) from investees, before tax	1	611
Federal and state income tax expense	13,410	12,195
Segment profit (loss)	30,031	29,016
Additions to long-lived assets	46,973	41,795
Equity investment in investees	14,541	14,540	14,540
Total segment assets	3,984,697	4,050,202	4,050,202
Reconciliation of segment profit to consolidated profit:
Number of transmission interconnection facility subsidiaries	2
Unallocated items:
Preferred dividends requirements	0	12
Net income applicable to common stock	30,031	29,004
Midstream [Member]
Revenue
Electric operations	0	0
Tolling operations	1,234	2,781
Other operations	1	1
Electric customer credits	0	0
Affiliate revenue	0	33
Operating revenue, net	1,235	2,815
Depreciation	1,532	1,456
Interest charges	1,471	583
Interest income	0	1
Equity income (loss) from investees, before tax	0	612
Federal and state income tax expense	739	(683)
Segment profit (loss)	1,090	(1,097)
Additions to long-lived assets	(3,802)	1,006
Equity investment in investees	0	0
Total segment assets	229,096	233,666
Reconciling Items [Member]
Revenue
Electric operations	0	0
Tolling operations	0	0
Other operations	497	485
Electric customer credits	0	0
Affiliate revenue	11,607	11,021
Operating revenue, net	12,104	11,506
Depreciation	224	241
Interest charges	619	1,567
Interest income	(44)	(60)
Equity income (loss) from investees, before tax	1	(1)
Federal and state income tax expense	(1,835)	(1,522)
Segment profit (loss)	2,136	83
Additions to long-lived assets	387	60
Equity investment in investees	9	8
Total segment assets	212,387	201,074
Eliminations [Member]
Revenue
Electric operations	0	0
Tolling operations	(1,234)	0
Other operations	0	(1)
Electric customer credits	0	0
Affiliate revenue	(11,952)	(11,253)
Operating revenue, net	(13,186)	(11,254)
Depreciation	1	0
Interest charges	48	62
Interest income	48	61
Equity income (loss) from investees, before tax	0	0
Federal and state income tax expense	(1)	0
Segment profit (loss)	0	0
Additions to long-lived assets	0	0
Equity investment in investees	0	0
Total segment assets	(144,101)	(111,009)
Unallocated Amount to Segment [Member]
Unallocated items:
Preferred dividends requirements		12
Cleco Power [Member]
Revenue
Electric operations	209,590	238,468
Tolling operations	0	0
Other operations	10,448	12,243
Electric customer credits	2,237	(434)
Affiliate revenue	345	346
Operating revenue, net	222,620	250,623
Depreciation	29,410	27,401
Interest charges	18,486	24,402
Interest income	30	113
Equity income (loss) from investees, before tax	0	0
Federal and state income tax expense	14,507	14,400
Segment profit (loss)	26,805	30,030
Additions to long-lived assets	50,388	40,729
Equity investment in investees	14,532	14,532	14,532
Total segment assets	$ 3,687,315	$ 3,726,471	$ 3,726,471