Summary of Significant Accounting Policies - Changes in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Receivable, threshold period past due	20 days
ACCOUNTS RECEIVABLE
Accounts receivable, beginning balance	$ 2,758	$ 3,005
Current period provision	1,874	2,498
Charge-offs	(2,859)	(4,092)
Recovery	267	641
Accounts receivable, ending balance	2,040	2,123
OTHER
Financing receivable, beginning balance	1,638	1,250
Current period provision	0	388
Charge-offs	0	0
Recovery	0	0
Financing receivable, ending balance	1,638	1,638
TOTAL
Total, beginning balance	4,396	4,255
Current period provision	1,874	2,886
Charge-offs	(2,859)	(4,092)
Recovery	267	641
Total, ending balance	3,678	3,761
CLECO POWER
ACCOUNTS RECEIVABLE
Accounts receivable, beginning balance	2,758	3,005
Current period provision	1,874	2,498
Charge-offs	(2,859)	(4,092)
Recovery	267	641
Accounts receivable, ending balance	$ 2,040	2,123
Accounting Standards Update 2016-13 | CECL adoption
ACCOUNTS RECEIVABLE
Accounts receivable, beginning balance		71
TOTAL
Total, beginning balance		71
Accounting Standards Update 2016-13 | CLECO POWER | CECL adoption
ACCOUNTS RECEIVABLE
Accounts receivable, beginning balance		$ 71