Recent Authoritative Guidance - ASU 2017-07 (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations	$ 27,967	$ 29,327
Total operating expenses	232,026	209,039
Operating income	44,734	41,462
Other expense	(3,554)	(2,938)
Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations		29,327
Total operating expenses		209,039
Operating income		41,462
Other expense		2,938
Payments for merger related costs	100
Accounting Standards Update 2017-07 | AS REPORTED
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations		31,892
Total operating expenses		211,703
Operating income		38,798
Other expense		(274)
Cleco Power
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations	27,307	30,264
Total operating expenses	228,866	207,278
Operating income	50,521	46,424
Other expense	$ (2,608)	(1,998)
Cleco Power | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations		30,264
Total operating expenses		207,278
Operating income		46,424
Other expense		1,998
Cleco Power | Accounting Standards Update 2017-07 | AS REPORTED
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations		31,988
Total operating expenses		209,002
Operating income		44,700
Other expense		$ (274)