Fair Value Accounting and Financial Instruments - Fair Value of Financial Assets and Liabilities Measured On A Recurring Basis (Details) - Measured on a Recurring Basis - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Asset description
Money market funds	$ 192,983	$ 145,033
Total assets	360,536	239,474
Liability description
Total liabilities	599	834
CLECO POWER
Asset description
Money market funds	103,711	82,411
Total assets	104,551	87,926
Liability description
Total liabilities	273	597
FTRs
Asset description
Derivative assets	1,114	6,977
Liability description
Derivative liabilities	599	834
FTRs | CLECO POWER
Asset description
Derivative assets	840	5,515
Liability description
Derivative liabilities	273	597
Natural gas derivatives
Asset description
Derivative assets	166,439	87,464
QUOTED PRICES IN ACTIVE MARKETS FOR IDENTICAL ASSETS (LEVEL 1)
Asset description
Money market funds	192,983	145,033
Total assets	192,983	145,033
Liability description
Total liabilities	0	0
QUOTED PRICES IN ACTIVE MARKETS FOR IDENTICAL ASSETS (LEVEL 1) | CLECO POWER
Asset description
Money market funds	103,711	82,411
Total assets	103,711	82,411
Liability description
Total liabilities	0	0
QUOTED PRICES IN ACTIVE MARKETS FOR IDENTICAL ASSETS (LEVEL 1) | FTRs
Asset description
Derivative assets	0	0
Liability description
Derivative liabilities	0	0
QUOTED PRICES IN ACTIVE MARKETS FOR IDENTICAL ASSETS (LEVEL 1) | FTRs | CLECO POWER
Asset description
Derivative assets	0	0
Liability description
Derivative liabilities	0	0
QUOTED PRICES IN ACTIVE MARKETS FOR IDENTICAL ASSETS (LEVEL 1) | Natural gas derivatives
Asset description
Derivative assets	0	0
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2)
Asset description
Money market funds	0	0
Total assets	166,439	87,464
Liability description
Total liabilities	0	0
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2) | CLECO POWER
Asset description
Money market funds	0	0
Total assets	0	0
Liability description
Total liabilities	0	0
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2) | FTRs
Asset description
Derivative assets	0	0
Liability description
Derivative liabilities	0	0
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2) | FTRs | CLECO POWER
Asset description
Derivative assets	0	0
Liability description
Derivative liabilities	0	0
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2) | Natural gas derivatives
Asset description
Derivative assets	166,439	87,464
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Asset description
Money market funds	0	0
Derivative assets	1,114	6,977
Total assets	1,114	6,977
Liability description
Derivative liabilities	599	834
Total liabilities	599	834
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) | CLECO POWER
Asset description
Money market funds	0	0
Derivative assets	840	5,515
Total assets	840	5,515
Liability description
Derivative liabilities	273	597
Total liabilities	273	597
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) | FTRs
Asset description
Derivative assets	1,114	6,977
Liability description
Derivative liabilities	599	834
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) | FTRs | CLECO POWER
Asset description
Derivative assets	840	5,515
Liability description
Derivative liabilities	273	597
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) | Natural gas derivatives
Asset description
Derivative assets	$ 0	$ 0