Common Stock, Stock-Based Compensation (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Apr. 30, 2016	Apr. 12, 2016	Dec. 31, 2016	Dec. 31, 2015
Predecessor [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit		$ 1.2		$ 2.4
Compensation expense, non-forfeitable dividends paid on non-vested stock not expected to vest and stock options		0.1		0.1
Amount of stock based compensation capitalized in property, plant, and equipment		0.6		0.8
Predecessor [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Merger expense due to accelerated vesting of LTIP shares	$ 2.3
Pre-tax compensation expense		$ 3.2		6.1
Cleco Power [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit			$ 0.4	0.8
Amount of stock based compensation capitalized in property, plant, and equipment			0.6	0.7
Cleco Power [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense			$ 1.0	$ 2.0