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		$ 1,905.9	$ 0.7	$ 435.3	$ 1,569.4	$ (109.5)	$ 1,895.9	$ 10.0
Balance (in shares) at Dec. 31, 2015			70.8
Increase (Decrease) in Shareholders' Equity
Net income		124.4			124.3		124.3	0.1
Cash dividends declared		(12.5)			(12.5)		(12.5)
Distribution of noncontrolling interest		(0.2)						(0.2)
Amortization of share-based payment awards		14.5		14.5			14.5
Issuance of common stock related to share-based payment awards (including income tax benefit of $1.6 million in 2016)		1.6		1.6			1.6
Issuance of common stock related to share-based payment awards (including income tax benefit of $1.6 million in 2016) (in shares)			0.1
Purchases of common stock tendered by employees to satisfy the required withholding taxes related to share-based payment awards		(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 (in shares)			(0.1)
Purchases of common stock		(18.4)		(18.4)			(18.4)
Purchases of common stock (in shares)			(0.4)
Acquisition of remaining 49% equity interest	[1]	(3.7)		(10.9)			(10.9)	7.2
Other comprehensive income (loss)		(30.7)				(28.9)	(28.9)	(1.8)
Balance as of end of period at Sep. 30, 2016		1,976.8	$ 0.7	418.0	1,681.2	(138.3)	1,961.6	15.2
Balance (in shares) at Sep. 30, 2016			70.4
Balance as of beginning of period at Dec. 31, 2016		$ 1,940.0	$ 0.7	399.9	1,679.3	(154.8)	1,925.0	15.0
Balance (in shares) at Dec. 31, 2016		69.9	69.9
Increase (Decrease) in Shareholders' Equity
Net income		$ 23.4			22.8		22.8	0.6
Cash dividends declared		(8.2)			(8.2)		(8.2)
Distribution of noncontrolling interest		(0.4)						(0.4)
Amortization of share-based payment awards		15.3		15.3			15.3
Issuance of common stock related to share-based payment awards (including income tax benefit of $1.6 million in 2016) (in shares)			(0.4)
Purchases of common stock tendered by employees to satisfy the required withholding taxes related to share-based payment awards		(4.0)		(4.0)			(4.0)
Purchases of common stock tendered by employees to satisfy the required withholding taxes related to share-based payment awards (in shares)			0.0
Purchases of common stock		(61.9)		(61.9)			(61.9)
Purchases of common stock (in shares)			(1.7)
Other comprehensive income (loss)		31.6				30.0	30.0	1.6
Balance as of end of period at Sep. 30, 2017		$ 1,935.8	$ 0.7	$ 349.3	$ 1,693.9	$ (124.8)	$ 1,919.0	$ 16.8
Balance (in shares) at Sep. 30, 2017		67.7	67.7

[1] Relates to Tobras. See Note 2. Acquisitions.