Affiliate Transactions (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	$ 0								$ 0
Affiliate revenue									0	202,000	1,564,000
Distribution payments to parent									63,700,000	291,219,000	183,700,000
Cleco Power [Member]
Related Party Transaction [Line Items]
Distribution payments to parent									58,000,000	130,000,000	150,000,000
Perryville [Member]
Related Party Transaction [Line Items]
Distribution payments to parent									1,500,000	700,000	700,000
Attala [Member]
Related Party Transaction [Line Items]
Distribution payments to parent									1,300,000	700,000	700,000
Acadia [Member]
Related Party Transaction [Line Items]
Affiliate revenue									0	202,000	1,564,000
Diversified Lands [Member]
Related Party Transaction [Line Items]
Distribution payments to parent									2,900,000	0	0
Midstream [Member]
Related Party Transaction [Line Items]
Distribution payments to parent									0	159,819,000	32,300,000
Cleco Power [Member]
Related Party Transaction [Line Items]
Affiliate revenue									1,372,000	1,389,000	1,371,000
Accounts receivable - affiliate	2,991,000				2,405,000				2,991,000	2,405,000
Accounts payable - affiliate	10,097,000				9,311,000				10,097,000	9,311,000
Distribution payments to parent	0	18,000,000	10,000,000	30,000,000	30,000,000	50,000,000	0	50,000,000	58,000,000	130,000,000	150,000,000
Transfer of pension plan liability and an equal amount of cash									2,161,000	2,101,000
Related Party Transaction, Other Revenues from Transactions with Related Party									40,000	155,000	277,000
Total Revenue from Affiliate Transactions									1,412,000	1,544,000	1,648,000
Cleco Power [Member] | Acadia Unit 1 [Member]
Related Party Transaction [Line Items]
Non-cash equity contributions from parent											225,700,000
Cleco Power [Member] | Cleco Corporation [Member]
Related Party Transaction [Line Items]
Accounts receivable - affiliate	139,000				18,000				139,000	18,000
Accounts payable - affiliate	1,140,000				827,000				1,140,000	827,000
Related Party Transaction, Other Revenues from Transactions with Related Party									0	10,000	118,000
Cleco Power [Member] | Support Group [Member]
Related Party Transaction [Line Items]
Affiliate revenue									1,335,000	1,349,000	1,332,000
Accounts receivable - affiliate	2,777,000				2,207,000				2,777,000	2,207,000
Accounts payable - affiliate	7,528,000				8,066,000				7,528,000	8,066,000
Transfer of pension plan liability and an equal amount of cash									1,881,000	1,844,000
Related Party Transaction, Other Revenues from Transactions with Related Party									0	0	4,000
Cleco Power [Member] | Support Group [Member] | Other Operating Expense [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party									43,171,000	43,124,000	39,633,000
Cleco Power [Member] | Support Group [Member] | Taxes other than income taxes [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party									(54,000)	(1,000)	(5,000)
Cleco Power [Member] | Support Group [Member] | Maintenance [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party									1,437,000	1,625,000	1,650,000
Cleco Power [Member] | Support Group [Member] | Other Expense [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party									932,000	1,244,000	1,050,000
Cleco Power [Member] | Generation Services [Member]
Related Party Transaction [Line Items]
Transfer of pension plan liability and an equal amount of cash									0	220,000
Cleco Power [Member] | Evangeline [Member]
Related Party Transaction [Line Items]
Affiliate revenue									23,000	26,000	26,000
Accounts receivable - affiliate	6,000				12,000				6,000	12,000
Accounts payable - affiliate	1,401,000				214,000				1,401,000	214,000
Related Party Transaction, Other Revenues from Transactions with Related Party									11,000	12,000	24,000
Cleco Power [Member] | Evangeline [Member] | Power purchased for utility customers [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party									25,559,000	0	0
Cleco Power [Member] | Evangeline [Member] | Other Expense [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party									0	4,000	0
Cleco Power [Member] | Perryville [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party									6,000	4,000	5,000
Cleco Power [Member] | Attala [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party									6,000	5,000	4,000
Cleco Power [Member] | Acadia [Member]
Related Party Transaction [Line Items]
Accounts receivable - affiliate	0				124,000				0	124,000
Accounts payable - affiliate	0				196,000				0	196,000
Cleco Power [Member] | Diversified Lands [Member]
Related Party Transaction [Line Items]
Accounts receivable - affiliate	42,000				20,000				42,000	20,000
Accounts payable - affiliate	23,000				3,000				23,000	3,000
Related Party Transaction, Other Revenues from Transactions with Related Party									17,000	124,000	122,000
Cleco Power [Member] | Diversified Lands [Member] | Other Expense [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party									0	82,000	19,000
Cleco Power [Member] | Midstream [Member]
Related Party Transaction [Line Items]
Affiliate revenue									14,000	14,000	13,000
Accounts receivable - affiliate	27,000				24,000				27,000	24,000
Accounts payable - affiliate	5,000				5,000				5,000	5,000
Transfer of pension plan liability and an equal amount of cash									$ 280,000	$ 37,000