Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees - Off-Balance Sheet Commitments and Guarantees (Details)	9 Months Ended
	Sep. 30, 2018 USD ($)
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
Indemnification Agreement
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	40,000,000
Indemnification Agreement including fundamental organizational structure
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	400,000,000
CLECO POWER | Indemnification Agreement
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	40,000,000
CLECO POWER | Indemnification Agreement including fundamental organizational structure
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	400,000,000
CLECO POWER | Financial Guarantee
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	$ 101,100,000