Schedule I Financial Statements of Cleco Holdings (Parent Company Only) - Condensed Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)	$ 31,797	$ 55,565	$ 44,746	$ 20,557	$ 10,377	$ 47,360	$ 25,839	$ 10,861	$ 152,665	$ 94,437	$ 138,080
Other comprehensive income (loss), net of tax
Postretirement benefits gain (loss) (net of tax benefit of $149, tax expense of $1,868, and tax benefit of $2,764, respectively)									(19,299)	5,296	(4,421)
Total other comprehensive (loss) income, net of tax									(19,299)	5,296	(4,421)
Comprehensive income, net of tax									133,366	99,733	133,659
Cleco Holdings
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)									152,665	94,437	138,080
Other comprehensive income (loss), net of tax
Postretirement benefits gain (loss) (net of tax benefit of $149, tax expense of $1,868, and tax benefit of $2,764, respectively)									(19,299)	5,296	(4,421)
Total other comprehensive (loss) income, net of tax									(19,299)	5,296	(4,421)
Comprehensive income, net of tax									$ 133,366	$ 99,733	$ 133,659