Consolidated Statements of Income and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Revenue	$ 10,150.8	$ 8,086.2	$ 19,332.2	$ 16,280.4
Cost of revenue	9,904.7	7,855.2	18,842.6	15,818.0
Gross profit	246.2	231.0	489.6	462.4
Operating expenses:
Compensation and employee benefits	110.2	102.3	224.1	206.8
General and administrative	74.9	77.4	147.2	154.0
Total operating expenses	185.1	179.7	371.3	360.9
Income from operations	61.1	51.2	118.3	101.6
Non-operating expenses, net:
Interest expense and other financing costs, net	(17.9)	(13.8)	(34.2)	(26.5)
Other expense, net	(1.6)	(2.6)	(3.9)	(4.1)
Total non-operating expenses, net	(19.5)	(16.4)	(38.1)	(30.6)
Income before income taxes	41.6	34.9	80.2	70.9
Provision for income taxes	12.4	4.6	19.7	9.6
Net income including noncontrolling interest	29.2	30.3	60.5	61.3
Net income attributable to noncontrolling interest	0.5	0.2	0.6	0.0
Net income attributable to World Fuel	$ 28.7	$ 30.0	$ 59.9	$ 61.4
Basic earnings per common share (in dollars per share)	$ 0.42	$ 0.44	$ 0.89	$ 0.90
Basic weighted average common shares (in shares)	67.7	68.4	67.6	68.5
Diluted earnings per common share (in dollars per share)	$ 0.42	$ 0.44	$ 0.88	$ 0.89
Diluted weighted average common shares (in shares)	68.0	68.7	67.9	68.9
Comprehensive income:
Net income including noncontrolling interest	$ 29.2	$ 30.3	$ 60.5	$ 61.3
Other comprehensive income (loss):
Foreign currency translation adjustments	(28.6)	11.2	(18.3)	17.6
Cash flow hedges, net of income tax expense of $3.1 for the three months ended June 30, 2018 and net of income tax benefit of $1.1 and income tax expense of $6.6 for the six months ended June 30, 2018 and 2017, respectively	6.9	0.0	(2.8)	10.5
Other comprehensive income (loss)	(21.7)	11.2	(21.1)	28.1
Comprehensive income including noncontrolling interest	7.5	41.5	39.3	89.4
Comprehensive (loss) income attributable to noncontrolling interest	(1.1)	1.1	(1.3)	1.0
Comprehensive income attributable to World Fuel	$ 8.6	$ 40.3	$ 40.7	$ 88.4