Correction of Previously Issued Financial Information - Consolidated Balance Sheets (Details) - USD ($) $ in Millions		Sep. 30, 2016		Dec. 31, 2015		Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	[1]	$ 872.3		$ 582.5		$ 609.6	$ 302.3
Accounts receivable, net	[1]	2,062.6		1,812.6
Inventories	[1]	484.5		359.1
Prepaid expenses	[1]	57.6		57.9
Short-term derivative assets, net	[1]	34.4		220.4
Other current assets	[1]	241.2		208.0
Current assets held for sale	[1]	0.0		5.5
Total current assets	[1]	3,752.5		3,246.0
Property and equipment, net	[1]	260.3		225.6
Goodwill	[1]	720.0		675.8
Identifiable intangible and other non-current assets	[1]	419.7		341.4
Non-current assets held for sale	[1]	0.0		36.5
Total assets	[1]	5,152.5		4,525.3
Current liabilities:
Short-term debt		28.8	[1]	25.5	[1]	25.5
Accounts payable	[1]	1,558.6		1,349.6
Customer deposits	[1]	106.5		118.3
Accrued expenses and other current liabilities	[1]	254.3		255.2
Current liabilities held for sale	[1]	0.0		5.6
Total current liabilities	[1]	1,948.2		1,754.2
Long-term debt		1,110.1	[1]	746.7	[1]	746.7
Non-current income tax liabilities, net	[1]	86.0		87.7
Other long-term liabilities	[1]	31.4		25.8
Non-current liabilities held for sale	[1]	0.0		5.0
Total liabilities	[1]	3,175.7		2,619.4
Commitments and contingencies	[1]
World Fuel shareholders' equity:
Preferred stock, $1.00 par value; 0.1 shares authorized, none issued	[1]	0.0		0.0
Common stock, $0.01 par value; 100 shares authorized, 70.8 issued and outstanding as of December 31, 2015	[1]	0.7		0.7
Capital in excess of par value	[1]	418.0		435.3
Retained earnings	[1]	1,681.2		1,569.4
Accumulated other comprehensive loss	[1]	(138.3)		(109.5)
Total World Fuel shareholders' equity	[1]	1,961.6		1,895.9
Noncontrolling interest equity	[1]	15.2		10.0
Total equity	[1]	1,976.8		1,905.9		$ 1,864.4	$ 1,859.4
Total liabilities and equity	[1]	5,152.5		4,525.3
As Reported
Current assets:
Cash and cash equivalents				582.5
Accounts receivable, net				1,812.6
Inventories				359.1
Prepaid expenses				57.9
Short-term derivative assets, net				227.2
Other current assets				209.8
Current assets held for sale				5.5
Total current assets				3,254.6
Property and equipment, net				225.6
Goodwill				675.8
Identifiable intangible and other non-current assets				356.9
Non-current assets held for sale				36.5
Total assets				4,549.4
Current liabilities:
Short-term debt				25.5
Accounts payable				1,349.6
Customer deposits				118.3
Accrued expenses and other current liabilities				263.8
Current liabilities held for sale				5.6
Total current liabilities				1,762.8
Long-term debt				746.7
Non-current income tax liabilities, net				87.7
Other long-term liabilities				25.8
Non-current liabilities held for sale				5.0
Total liabilities				2,628.0
Commitments and contingencies
World Fuel shareholders' equity:
Preferred stock, $1.00 par value; 0.1 shares authorized, none issued				0.0
Common stock, $0.01 par value; 100 shares authorized, 70.8 issued and outstanding as of December 31, 2015				0.7
Capital in excess of par value				435.3
Retained earnings				1,588.6
Accumulated other comprehensive loss				(113.2)
Total World Fuel shareholders' equity				1,911.4
Noncontrolling interest equity				10.0
Total equity				1,921.4
Total liabilities and equity				4,549.4
Adjustment
Current assets:
Cash and cash equivalents				0.0
Accounts receivable, net				0.0
Inventories				0.0
Prepaid expenses				0.0
Short-term derivative assets, net				(6.8)
Other current assets				(1.8)
Current assets held for sale				0.0
Total current assets				(8.6)
Property and equipment, net				0.0
Goodwill				0.0
Identifiable intangible and other non-current assets				(15.5)
Non-current assets held for sale				0.0
Total assets				(24.1)
Current liabilities:
Short-term debt				0.0
Accounts payable				0.0
Customer deposits				0.0
Accrued expenses and other current liabilities				(8.6)
Current liabilities held for sale				0.0
Total current liabilities				(8.6)
Long-term debt				0.0
Non-current income tax liabilities, net				0.0
Other long-term liabilities				0.0
Non-current liabilities held for sale				0.0
Total liabilities				(8.6)
Commitments and contingencies
World Fuel shareholders' equity:
Preferred stock, $1.00 par value; 0.1 shares authorized, none issued				0.0
Common stock, $0.01 par value; 100 shares authorized, 70.8 issued and outstanding as of December 31, 2015				0.0
Capital in excess of par value				0.0
Retained earnings				(19.2)
Accumulated other comprehensive loss				3.7
Total World Fuel shareholders' equity				(15.5)
Noncontrolling interest equity				0.0
Total equity				(15.5)
Total liabilities and equity				(24.1)
Adjustment | Correction to provision for income taxes
World Fuel shareholders' equity:
Retained earnings		$ (20.0)		$ (12.5)

[1] Amounts may not add due to rounding