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, 2018	$ 1,831.6	$ 0.7	$ 340.4	$ 1,606.1	$ (131.7)	$ 1,815.4	$ 16.1
Balance (in shares) at Dec. 31, 2018		67.0
Increase (Decrease) in Shareholders' Equity
Net income	37.3			37.2		37.2	0.1
Cash dividends declared	(4.0)			(4.0)		(4.0)
Amortization of share-based payment awards	4.0		4.0			4.0
Issuance (cancellation) of common stock related to share-based payment awards (in shares)		0.1
Purchases of common stock tendered by employees to satisfy the required withholding taxes related to share-based payment awards	(1.4)		(1.4)			(1.4)
Other comprehensive income (loss)	(11.7)				(11.0)	(11.0)	(0.8)
Balance as of end of period at Mar. 31, 2019	1,855.8	$ 0.7	343.0	1,639.3	(142.7)	1,840.3	15.5
Balance (in shares) at Mar. 31, 2019		67.1
Balance as of beginning of period at Dec. 31, 2018	1,831.6	$ 0.7	340.4	1,606.1	(131.7)	1,815.4	16.1
Balance (in shares) at Dec. 31, 2018		67.0
Increase (Decrease) in Shareholders' Equity
Issuance (cancellation) of common stock related to share-based payment awards	0.0
Balance as of end of period at Dec. 31, 2019	$ 1,893.9	$ 0.7	274.7	1,761.3	(146.3)	1,890.4	3.5
Balance (in shares) at Dec. 31, 2019	65.2	65.2
Increase (Decrease) in Shareholders' Equity
Net income	$ 41.6			41.4		41.4	0.2
Cash dividends declared	(6.5)			(6.5)		(6.5)
Amortization of share-based payment awards	(1.8)		(1.8)			(1.8)
Issuance (cancellation) of common stock related to share-based payment awards	1.2		1.2			1.2
Issuance (cancellation) of common stock related to share-based payment awards (in shares)		0.2
Purchases of common stock tendered by employees to satisfy the required withholding taxes related to share-based payment awards	(1.5)		(1.5)			(1.5)
Purchases of common stock	(55.6)		(55.6)			(55.6)
Purchases of common stock (in shares)		(2.2)
Other comprehensive income (loss)	(11.3)				(11.3)	(11.3)	0.0
Other	1.2	$ (0.1)	1.2			1.2
Balance as of end of period at Mar. 31, 2020	$ 1,850.1	$ 0.6	$ 218.2	$ 1,785.1	$ (157.5)	$ 1,846.4	$ 3.7
Balance (in shares) at Mar. 31, 2020	63.2	63.2