Intangible Assets, Intangible Liabilities, and Goodwill - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Aug. 01, 2019	Feb. 04, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Expected amortization in the year 2020	$ 26,372,000
Goodwill	1,490,797,000			$ 1,490,797,000	$ 1,490,797,000
Carrying value of equity	2,643,006,000			2,124,740,000	2,096,357,000	$ 2,046,763,000
CLECO POWER
Acquired Finite-Lived Intangible Assets [Line Items]
Expected amortization in the year 2020	500,000
Impairment of goodwill	0
Equity, fair value		$ 3,970,000,000
Carrying value of equity	$ 1,713,392,000	$ 3,400,000,000		$ 1,594,533,000	$ 1,550,679,000	$ 1,535,202,000
Excess of the fair value over the carrying value, percent		16.80%
Excess of the fair value over the carrying value		$ 570,400,000
Accumulated impairment charges		$ 0
LTSA
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible liabilities			$ 24,100,000
Transmission Service Agreement
Acquired Finite-Lived Intangible Assets [Line Items]
Preliminary fair value of intangible liabilities			$ 14,200,000