Consolidated Statements of Shareholders' Equity - USD ($) shares in Millions, $ in Millions		Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss	Total World Fuel Shareholders' Equity	Noncontrolling Interest Equity
Balance as of beginning of period at Dec. 31, 2015	[1]	$ 1,905.9	$ 0.7	$ 435.3	$ 1,569.4	$ (109.5)	$ 1,895.9	$ 10.0
Balance (in shares) at Dec. 31, 2015	[1]		70.8
Increase (Decrease) in Shareholders' Equity
Net income	[1]	51.6			51.8		51.8	(0.1)
Cash dividends declared	[1]	(4.2)			(4.2)		(4.2)
Distribution of noncontrolling interest	[1]	(0.2)						(0.2)
Amortization of share-based payment awards	[1]	4.0		4.0			4.0
Issuance of common stock related to share-based payment awards (in shares)	[1]		0.1
Purchases of common stock tendered by employees to satisfy the required withholding taxes related to share-based payment awards	[1]	(0.9)		(0.9)			(0.9)
Other comprehensive income (loss)	[1]	1.0				(0.5)	(0.5)	1.6
Balance as of end of period at Mar. 31, 2016	[1]	1,957.2	$ 0.7	438.4	1,616.9	(110.0)	1,946.1	11.2
Balance (in shares) at Mar. 31, 2016	[1]		70.9
Balance as of beginning of period at Dec. 31, 2016	[1]	$ 1,940.0	$ 0.7	399.9	1,679.3	(154.8)	1,925.0	15.0
Balance (in shares) at Dec. 31, 2016	[1]	69.9	69.9
Increase (Decrease) in Shareholders' Equity
Net income	[1]	$ 31.1			31.3		31.3	(0.3)
Cash dividends declared	[1]	(4.1)			(4.1)		(4.1)
Distribution of noncontrolling interest	[1]	(0.1)						(0.1)
Amortization of share-based payment awards	[1]	4.2		4.2			4.2
Purchases of common stock tendered by employees to satisfy the required withholding taxes related to share-based payment awards	[1]	(1.2)		(1.2)			(1.2)
Purchases of common stock	[1]	(11.1)		(11.1)			(11.1)
Purchases of common stock (in shares)	[1]		(0.3)
Other comprehensive income (loss)	[1]	16.9				16.7	16.7	0.2
Balance as of end of period at Mar. 31, 2017	[1]	$ 1,975.6	$ 0.7	$ 391.8	$ 1,706.5	$ (138.1)	$ 1,960.8	$ 14.8
Balance (in shares) at Mar. 31, 2017	[1]	69.6	69.6

[1] Amounts may not add due to rounding