Summary Quarterly Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Summary of unaudited quarterly result
Revenue	$ 7,792.1	$ 7,399.8	$ 6,633.0	$ 5,190.8	$ 6,733.6	$ 7,810.7	$ 8,496.4	$ 7,340.7	$ 27,015.8	$ 30,381.4	$ 43,391.8
Gross profit	222.3	236.7	218.5	221.5	230.2	226.7	190.4	213.6	899.0	861.0	819.1
Net income including noncontrolling interest	2.1	43.0	29.8	51.6	49.6	42.7	29.0	49.3	126.4	170.5	221.1
Net income attributable to World Fuel	$ 2.2	$ 42.7	$ 30.0	$ 51.8	$ 49.9	$ 43.7	$ 30.5	$ 50.3	$ 126.5	$ 174.5	$ 224.5
Basic earnings per common share (in dollars per share)	$ 0.03	$ 0.62	$ 0.43	$ 0.74	$ 0.72	$ 0.62	$ 0.43	$ 0.71	$ 1.82	$ 2.49	$ 3.17
Diluted earnings per common share (in dollars per share)	$ 0.03	$ 0.61	$ 0.43	$ 0.74	$ 0.71	$ 0.62	$ 0.43	$ 0.70	$ 1.81	$ 2.47	$ 3.15
Employment Agreement
Summary of unaudited quarterly result
Severance termination charge, net of tax								$ 2.3
Severance termination charge, impact on basic and diluted earnings per share (in dollars per share)								$ 0.03