Consolidated Statements of Income and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 10,429.5	$ 8,543.0	$ 29,761.7	$ 24,823.4
Cost of revenue	10,162.8	8,303.1	29,005.4	24,121.1
Gross profit	266.7	239.9	756.3	702.3
Operating expenses:
Compensation and employee benefits	117.9	107.6	342.0	314.5
General and administrative	70.6	71.0	217.8	225.0
Total operating expenses	188.5	178.6	559.8	539.5
Income from operations	78.2	61.3	196.4	162.8
Non-operating expenses, net:
Interest expense and other financing costs, net	(18.3)	(15.8)	(52.5)	(42.2)
Other income (expense), net	1.9	(0.9)	(2.0)	(5.0)
Total non-operating expenses, net	(16.4)	(16.7)	(54.5)	(47.3)
Income before income taxes	61.8	44.6	142.0	115.6
Provision for income taxes	23.0	82.6	42.7	92.2
Net income (loss) including noncontrolling interest	38.7	(37.9)	99.2	23.4
Net income attributable to noncontrolling interest	0.6	0.6	1.1	0.6
Net income (loss) attributable to World Fuel	$ 38.2	$ (38.5)	$ 98.1	$ 22.8
Basic earnings per common share (in dollars per share)	$ 0.57	$ (0.57)	$ 1.45	$ 0.33
Basic weighted average common shares (in shares)	67.5	67.9	67.5	68.3
Diluted earnings per common share (in dollars per share)	$ 0.56	$ (0.57)	$ 1.45	$ 0.33
Diluted weighted average common shares (in shares)	67.7	68.2	67.8	68.6
Comprehensive income:
Net income including noncontrolling interest	$ 38.7	$ (37.9)	$ 99.2	$ 23.4
Other comprehensive income (loss):
Foreign currency translation adjustments	(4.7)	12.2	(23.0)	29.8
Cash flow hedges, net of income tax benefit of $3.5 and $5.5 for the three months ended September 30, 2018 and 2017, respectively, and net of income tax benefit of $5.2 and income tax expense of $1.1 for the nine months ended September 30, 2018 and 2017, respectively	(5.6)	(8.7)	(8.4)	1.8
Other comprehensive income (loss)	(10.3)	3.5	(31.4)	31.6
Comprehensive income (loss) including noncontrolling interest	28.5	(34.4)	67.8	55.0
Comprehensive income (loss) attributable to noncontrolling interest	0.1	1.1	(1.2)	2.2
Comprehensive income (loss) attributable to World Fuel	$ 28.4	$ (35.5)	$ 69.1	$ 52.8