Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Numerator:
Net income attributable to World Fuel	[1]	$ 31.3	$ 51.8
Denominator:
Weighted average common shares for basic earnings per common share (in shares)	[1]	68.7	69.5
Effect of dilutive securities (in shares)		0.4	0.5
Weighted average common shares for diluted earnings per common share (in shares)	[1]	69.2	70.0
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)		0.6	0.9
Basic earnings per common share (in dollars per share)	[1]	$ 0.46	$ 0.74
Diluted earnings per common share (in dollars per share)	[1]	$ 0.45	$ 0.74

[1] Amounts may not add due to rounding