Common Stock, Long-Term Incentive Compensation Plan, Non-vested Stock and Common Stock Equivalent Units (Details) - Predecessor [Member] - Restricted Stock [Member] - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Apr. 12, 2016	Dec. 31, 2015
Non-Vested Stock, Fair Value Assumptions [Abstract]
Expected term (in years)		3 years
Volatility of Cleco stock (in hundredths)		15.80%
Correlation between Cleco stock volatility and peer group (in hundredths)		63.10%
Expected dividend yield (in hundredths)		2.90%
Weighted average fair value (Monte Carlo model) (in dollars per share)		$ 45.60
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Fair value of shares of non-vested stock vested during period	$ 10.1	$ 3.3
2010 Long-Term Incentive Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Non-vested shares of common stock granted during the year (in shares)	0