Fair Value Accounting Instruments - Fair Value of Financial Assets and Liabilities Measured On A Recurring Basis (Details) - Measured On A Recurring Basis - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Asset Description
Short-term investments	$ 242,596	$ 179,241
Total assets	250,725	287,457
Liability Description
Total liabilities	15,786	7,274
CLECO POWER
Asset Description
Short-term investments	169,606	139,752
Total assets	172,693	142,322
Liability Description
Total liabilities	15,112	4,864
FTRs
Asset Description
Derivative assets	3,087	2,570
Liability Description
Derivative liabilities	781	294
FTRs | CLECO POWER
Asset Description
Derivative assets	3,087	2,570
Liability Description
Derivative liabilities	781	294
Natural Gas Derivatives
Asset Description
Derivative assets	5,042	105,646
Liability Description
Derivative liabilities	15,005	6,980
Natural Gas Derivatives | CLECO POWER
Liability Description
Derivative liabilities	14,331	4,570
QUOTED PRICES IN ACTIVE MARKETS FOR IDENTICAL ASSETS (LEVEL 1)
Asset Description
Short-term investments	242,596	179,241
Total assets	242,596	179,241
Liability Description
Total liabilities	0	0
QUOTED PRICES IN ACTIVE MARKETS FOR IDENTICAL ASSETS (LEVEL 1) | CLECO POWER
Asset Description
Short-term investments	169,606	139,752
Total assets	169,606	139,752
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
Liability Description
Derivative liabilities	0	0
QUOTED PRICES IN ACTIVE MARKETS FOR IDENTICAL ASSETS (LEVEL 1) | Natural Gas Derivatives | CLECO POWER
Liability Description
Derivative liabilities	0	0
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2)
Asset Description
Short-term investments	0	0
Total assets	5,042	105,646
Liability Description
Total liabilities	15,005	6,980
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2) | CLECO POWER
Asset Description
Short-term investments	0	0
Total assets	0	0
Liability Description
Total liabilities	14,331	4,570
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	5,042	105,646
Liability Description
Derivative liabilities	15,005	6,980
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2) | Natural Gas Derivatives | CLECO POWER
Liability Description
Derivative liabilities	14,331	4,570
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Asset Description
Short-term investments	0	0
Total assets	3,087	2,570
Liability Description
Total liabilities	781	294
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) | CLECO POWER
Asset Description
Short-term investments	0	0
Total assets	3,087	2,570
Liability Description
Total liabilities	781	294
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) | FTRs
Asset Description
Derivative assets	3,087	2,570
Liability Description
Derivative liabilities	781	294
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) | FTRs | CLECO POWER
Asset Description
Derivative assets	3,087	2,570
Liability Description
Derivative liabilities	781	294
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) | Natural Gas Derivatives
Asset Description
Derivative assets	0	0
Liability Description
Derivative liabilities	0	0
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) | Natural Gas Derivatives | CLECO POWER
Liability Description
Derivative liabilities	$ 0	$ 0