Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees, Off-Balance Sheet Commitments and Guarantees (Details) $ in Millions	Jun. 30, 2017 USD ($)
Performance Guarantee
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 42.4
Indemnification Agreement
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	40.0
Indemnification Agreement including fundamental organizational structure
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	400.0
Cleco Power | Indemnification Agreement
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	40.0
Cleco Power | Indemnification Agreement including fundamental organizational structure
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	400.0
Cleco Power | Financial Guarantee
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 106.5