Common Stock, Long-Term Incentive Compensation Plan, Non-vested Stock and Common Stock Equivalent Units (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended			72 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015
2000 Long-Term Incentive Compensation Plan [Member]
Non-Vested Stock, Activity [Roll Forward]
Shares, granted (in shares)				0
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
Restricted Stock [Member]
Non-Vested Stock, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted average grant date fair value, non-vested, beginning of period (in dollars per share)	$ 43.29
Weighted average grant date fair value, non-vested, granted (in dollars per share)	54.74
Weighted average grant date fair value, non-vested, vested (in dollars per share)	40.26
Weighted average grant date fair value, non-vested, forfeited (in dollars per share)	42.75
Weighted average grant date fair value, non-vested, end of period (in dollars per share)	$ 48.11	$ 43.29		$ 48.11
Non-Vested Stock, Activity [Roll Forward]
Shares, non-vested, beginning of period (in shares)	301,049
Shares, granted (in shares)	90,050
Shares, vested (in shares)	(82,322)
Shares, forfeited (in shares)	(38,789)
Shares, non-vested, end of period (in shares)	269,988	301,049		269,988
Non-Vested Stock, Fair Value Assumptions [Abstract]
Expected term (in years)	3 years	3 years	3 years
Volatility of Cleco stock (in hundredths)	15.80%	17.30%	18.10%
Correlation between Cleco stock volatility and peer group (in hundredths)	63.10%	66.50%	69.70%
Expected dividend yield (in hundredths)	2.92%	3.00%	3.20%
Weighted average fair value (Monte Carlo model) (in dollars per share)	$ 45.60	$ 54.58	$ 42.66
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)	90,050
Fair value of shares of non-vested stock vested during period	$ 3.3	$ 5.6	$ 5.2
Restricted Stock [Member] | 2000 Long-Term Incentive Compensation Plan [Member]
Non-Vested Stock, Activity [Roll Forward]
Shares, non-vested, end of period (in shares)	0			0
Restricted Stock [Member] | 2010 Long-Term Incentive Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Target and opportunity shares for which restrictions had not lapsed	392,954			392,954
Non-vested shares granted with only a service period requirement that had not yet been completed	73,511			73,511
Common Stock Equivalent Units [Member]
Non-Vested Stock, Activity [Roll Forward]
Shares, granted (in shares)	0	0	0
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	0	0
Common Stock Equivalent Units [Member] | 2000 Long-Term Incentive Compensation Plan [Member]
Non-Vested Stock, Activity [Roll Forward]
Shares, non-vested, end of period (in shares)	0			0
Treasury Stock [Member] | Restricted Stock [Member] | 2010 Long-Term Incentive Compensation Plan [Member]
Non-Vested Stock, Activity [Roll Forward]
Shares, granted (in shares)	90,050
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)	90,050