Affiliate Transactions (Details) - USD ($)	3 Months Ended								9 Months Ended		12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Affiliate Transaction [Line Items]
Distributions to parent	$ 10,850,000	$ 20,600,000	$ 20,400,000	$ 19,500,000	$ 110,000	$ 28,300,000	$ 26,700,000	$ 28,955,000
SUCCESSOR
Affiliate Transaction [Line Items]
Distributions to parent									$ 88,765,000		$ 71,350,000	$ 84,065,000
Affiliate revenue										$ 0	0	0
Cleco Holdings | Cleco Group
Affiliate Transaction [Line Items]
Accounts receivable - affiliate	0										0
Accounts payable - affiliate	0				0						0	0
Cleco Holdings | SUCCESSOR | Cleco Group
Affiliate Transaction [Line Items]
Contribution from member										100,700,000
Distributions to parent										$ 88,800,000	71,400,000	84,100,000
Cleco Holdings | MAXIMUM | Cleco Group
Affiliate Transaction [Line Items]
Accounts receivable - affiliate					600,000							600,000
CLECO POWER
Affiliate Transaction [Line Items]
Accounts receivable - affiliate	3,318,000				1,355,000						3,318,000	1,355,000
Accounts payable - affiliate	7,843,000				8,697,000						7,843,000	8,697,000
Contribution from member													$ 50,000,000
Distributions to parent	0	$ 50,400,000	$ 43,000,000	$ 28,000,000	60,000,000	$ 15,000,000	$ 25,000,000	$ 35,000,000			121,400,000	135,000,000	110,000,000
Affiliate revenue											874,000	851,000	884,000
Other income											1,092,000	494,000	31,000
Total											1,966,000	1,345,000	915,000
CLECO POWER | Cleco Group
Affiliate Transaction [Line Items]
Accounts receivable - affiliate	699,000				743,000						699,000	743,000
Accounts payable - affiliate	88,000				113,000						88,000	113,000
Contribution from member											0	0
Distributions to parent											121,400,000	135,000,000	110,000,000
Other income											1,092,000	494,000	19,000
Non-cash equity contributions from parent													50,000,000
CLECO POWER | Cleco Group | Other expense
Affiliate Transaction [Line Items]
Charges from each affiliate											1,007,000	361,000	0
CLECO POWER | Support Group
Affiliate Transaction [Line Items]
Accounts receivable - affiliate	2,619,000				608,000						2,619,000	608,000
Accounts payable - affiliate	7,755,000				8,582,000						7,755,000	8,582,000
Affiliate revenue											874,000	851,000	884,000
Transfer of pension plan liability and an equal amount of assets											1,963,000	1,812,000
CLECO POWER | Support Group | Other operations and maintenance
Affiliate Transaction [Line Items]
Charges from each affiliate											56,669,000	50,572,000	48,371,000
CLECO POWER | Support Group | Taxes other than income taxes
Affiliate Transaction [Line Items]
Charges from each affiliate											6,000	(13,000)	10,000
CLECO POWER | Support Group | Other expense
Affiliate Transaction [Line Items]
Charges from each affiliate											290,000	255,000	106,000
CLECO POWER | Perryville
Affiliate Transaction [Line Items]
Other income											0	0	$ 12,000
CLECO POWER | Other
Affiliate Transaction [Line Items]
Accounts receivable - affiliate	0				4,000						0	4,000
Accounts payable - affiliate	$ 0				$ 2,000						$ 0	$ 2,000