Summary of Significant Accounting Policies - Recent Authoritative Guidance Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2019
Accounting Standards Update 2016-02 | Subsequent Event
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
ROU assets				$ 16,600,000
Lease liabilities				$ 16,000,000
Accounting Standards Update 2016-15
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other deferred accounts			$ 18,600,000
Payments of long-term debt prepayments			18,600,000
AOCI
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of effect of tax rate change	$ 600,000
6.65% Senior Notes | Senior Notes | Accounting Standards Update 2016-15
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amount of principal redeemed			$ 250,000,000.0
Interest rate			6.65%
CLECO POWER
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other deferred accounts	(5,421,000)	$ (8,137,000)	$ (3,249,000)
Payments of long-term debt prepayments	0	$ 0	$ 18,569,000
Reclassification of effect of tax rate change	2,496,000
CLECO POWER | AOCI
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of effect of tax rate change	$ 2,500,000