Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees - Off-Balance Sheet Commitments and Guarantees (Details) - USD ($)	1 Months Ended		3 Months Ended
	Mar. 31, 2021	Feb. 28, 2021	Mar. 31, 2021
Guarantor Obligations [Line Items]
Guarantor obligations, collateral held directly or by third parties, amount			$ 0
Performance Guarantee
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	$ 42,400,000		42,400,000
Indemnification Agreement
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	40,000,000.0		40,000,000.0
Indemnification Agreement including fundamental organizational structure
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	400,000,000.0		400,000,000.0
CLECO POWER
Guarantor Obligations [Line Items]
Guarantor obligations, collateral held directly or by third parties, amount			0
CLECO POWER | Letters of Credit
Guarantor Obligations [Line Items]
Incremental collateral posted		$ 25,000,000.0
CLECO POWER | Letters of Credit | Deferred storm restoration costs - Winter Storms Uri & Viola
Guarantor Obligations [Line Items]
Incremental collateral posted		25,000,000.0
Collateral returned	24,900,000
CLECO POWER | Indemnification Agreement
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	40,000,000.0		40,000,000.0
CLECO POWER | Indemnification Agreement including fundamental organizational structure
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	400,000,000.0		400,000,000.0
CLECO POWER | Financial Guarantee
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	25,000,000.0		$ 25,000,000.0
Cleco Cajun | Letters of Credit
Guarantor Obligations [Line Items]
Incremental collateral posted		8,800,000
Cleco Cajun | Letters of Credit | Deferred storm restoration costs - Winter Storms Uri & Viola
Guarantor Obligations [Line Items]
Incremental collateral posted		$ 8,800,000
Collateral returned	$ 6,500,000