Summary of Significant Accounting Policies - Changes in Allowance for Credit Losses (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Accounting Policies [Abstract]
Receivable, threshold period past due	20 days	20 days
ACCOUNTS RECEIVABLE
Accounts receivable, beginning balance	$ 3,486	$ 3,005
Current period provision	2,041	5,675
Charge-offs		(4,091)
Recovery	54	921
Balances, Sept. 30, 2020	5,581	5,581
OTHER
Financing receivable, beginning balance	1,638	1,250
Current period provision	0	388
Charge-offs		0
Recovery	0	0
Balances, Sept. 30, 2020	1,638	1,638
TOTAL
Total, beginning balance	5,124	4,255
Current period provision	2,041	6,063
Charge-offs		(4,091)
Recovery	54	921
Balances, Sept. 30, 2020	7,219	$ 7,219
CLECO POWER
Financing Receivable, Allowance for Credit Loss [Line Items]
Past due balances, repayment plan, period		18 months
ACCOUNTS RECEIVABLE
Accounts receivable, beginning balance	3,486	$ 3,005
Current period provision	2,041	5,675
Charge-offs		(4,091)
Recovery	54	921
Balances, Sept. 30, 2020	5,581	5,581
Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment
ACCOUNTS RECEIVABLE
Accounts receivable, beginning balance		100
TOTAL
Balances, Sept. 30, 2020	71	71
Accounting Standards Update 2016-13 | CLECO POWER | Cumulative Effect, Period of Adoption, Adjustment
ACCOUNTS RECEIVABLE
Balances, Sept. 30, 2020	$ 71	$ 71