Fair Value Accounting Fair Value Accounting, Concentration of Risk (Details) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012
Established guidelines for short-term investments to mitigate potential credit risk [Abstract]
Percentage Of Investments In Securities		5.00%
Percentage Of Portfolio		50.00%
Minimum assets under management in money market funds	$ 15,000,000,000	$ 15,000,000,000
Minimum existence of investments (in years)	2 years
Maximum Amount of Loss [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentrations of credit risk through short-term investments	51,500,000	51,500,000
Concentrations of credit risk through their short-term investments in cash	15,900,000	15,900,000
Concentrations of credit risk through their short-term investments in restricted cash	35,600,000	35,600,000
Cleco Power [Member] | Maximum Amount of Loss [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentrations of credit risk through short-term investments	43,000,000	43,000,000
Concentrations of credit risk through their short-term investments in cash	7,500,000	7,500,000
Concentrations of credit risk through their short-term investments in restricted cash	$ 35,500,000	$ 35,500,000