Affiliate Transactions - Summary of Balances Payable To or Due From Affiliates (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
ACCOUNTS RECEIVABLE	$ 3,038	$ 1,663
ACCOUNTS PAYABLE	41,283	41,283
CLECO POWER
Related Party Transaction [Line Items]
ACCOUNTS RECEIVABLE	13,982	14,605
ACCOUNTS PAYABLE	69,356	72,068
CLECO POWER | Cleco Holdings
Related Party Transaction [Line Items]
ACCOUNTS RECEIVABLE	10,712	10,353
ACCOUNTS PAYABLE	57,825	57,713
CLECO POWER | Support Group
Related Party Transaction [Line Items]
ACCOUNTS RECEIVABLE	2,388	3,248
ACCOUNTS PAYABLE	11,514	14,355
CLECO POWER | Cleco Cajun
Related Party Transaction [Line Items]
ACCOUNTS RECEIVABLE	882	1,004
ACCOUNTS PAYABLE	$ 17	$ 0