Schedule I Financial Statements of Cleco Holdings (Parent Company Only) - Condensed Statements of Comprehensive Income Parenthetical (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Tax (expense) benefit of postretirement benefits gain (loss)	$ 2,922	$ 6,808	$ 1,868
Cleco Holdings
Condensed Financial Statements, Captions [Line Items]
Tax (expense) benefit of postretirement benefits gain (loss)	$ 2,922	$ 6,808	$ 1,868

Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income of defined benefit plan.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
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