Debt - Credit Facilities (Details)	12 Months Ended
	Dec. 31, 2020 USD ($)	May 15, 2020	Feb. 04, 2019
Line of Credit
Line of Credit Facility [Line Items]
Borrowings outstanding	$ 75,000,000.0
Cleco Holdings
Line of Credit Facility [Line Items]
Ratio of total indebtedness to total capitalization			0.65
Cleco Holdings | MAXIMUM
Line of Credit Facility [Line Items]
Ratio of total indebtedness to total capitalization		0.65
Cleco Holdings | Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	175,000,000.0
Borrowings outstanding	0
Line of credit facility, remaining borrowing capacity	$ 475,000,000.0
Commitment fees	0.30%
Higher fees if downgraded	0.50%
Additional interest if downgraded	0.50%
Cleco Holdings | Line of Credit | ABR
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.875%
Cleco Holdings | Line of Credit | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.875%
CLECO POWER | MAXIMUM
Line of Credit Facility [Line Items]
Ratio of total indebtedness to total capitalization	0.65	65
CLECO POWER | Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 300,000,000.0
Borrowings outstanding	$ 75,000,000.0
Higher fees if downgraded	0.125%
Additional interest if downgraded	0.125%
CLECO POWER | Line of Credit | ABR
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.25%
Commitment fees	0.15%
CLECO POWER | Line of Credit | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.25%