Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator:
Net income attributable to World Fuel	[1]	$ 42.7	$ 43.7	$ 124.3	$ 124.5
Denominator:
Weighted average common shares for basic earnings per common share (in shares)	[1]	69.1	70.0	69.4	70.5
Effect of dilutive securities (in shares)		0.4	0.3	0.5	0.5
Weighted average common shares for diluted earnings per common share (in shares)	[1]	69.5	70.3	69.9	71.0
Weighted average securities which are not included in the calculation of diluted earnings per common share because their impact is anti-dilutive or their performance conditions have not been met (in shares)		1.3	1.5	1.3	1.0
Basic earnings per common share (in dollars per share)	[1]	$ 0.62	$ 0.62	$ 1.79	$ 1.77
Diluted earnings per common share (in dollars per share)	[1]	$ 0.61	$ 0.62	$ 1.78	$ 1.75

[1] Amounts may not add due to rounding