Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Basis of Presentation and Significant Accounting Policies
Basis of Presentation	Basis of Presentation The consolidated financial statements and related notes include our parent company and all wholly‑owned and majority‑owned subsidiaries and joint ventures where we exercise control. The decision of whether or not to consolidate an entity requires consideration of majority voting interests, as well as effective economic or other control over the entity. The consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP"). Our fiscal year-end is as of and for the year ended December 31 for each year presented. All significant transactions among our businesses have been eliminated.
New Accounting Standards	New Accounting Standards Adoption of New Accounting Standards Business Combinations (Topic 805): Simplifying the Accounting for Measurement - Period Adjustments. In September 2015, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) 2015-16 to simplify the accounting for adjustments made to provisional amounts recognized in a business combination; the amendments eliminate the requirement to retrospectively account for those adjustments. The ASU requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. It also requires that the acquirer record, in the same period’s financial statements, the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. This update became effective at the beginning of our 2016 fiscal year. The adoption of this ASU did not have a significant impact on our consolidated financial statements and disclosures. Interest: Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs. In April 2015, ASU 2015-03 was issued which requires that debt issuance costs related to a recognized debt liability, is presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this ASU. This update became effective at the beginning of our 2016 fiscal year. The adoption of this ASU did not have a significant impact on our consolidated financial statements and disclosures. Consolidation (Topic 810): Amendments to the Consolidation Analysis. In February 2015, ASU 2015-02 was issued and is intended to improve targeted areas of consolidation guidance for legal entities such as limited partnerships, limited liability corporations, and securitization structures. This update became effective at the beginning of our 2016 fiscal year. The adoption of this ASU did not have a significant impact on our consolidated financial statements and disclosures. Income Statement - Extraordinary and Unusual Items (Subtopic 225-20): Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items. In January 2015, ASU 2015-01 was issued, which eliminates the concept of extraordinary items. This update became effective at the beginning of our 2016 fiscal year. The adoption of this ASU did not have a significant impact on our consolidated financial statements and disclosures. Derivatives and Hedging (Topic 815): Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity. In November 2014, ASU 2014-16 was issued which clarifies how current generally accepted accounting principles in the United States should be interpreted in evaluating the economic characteristics and risks of a host contract in a hybrid financial instrument that is issued in the form of a share. This update became effective at the beginning of our 2016 fiscal year. The adoption of this ASU did not have a significant impact on our consolidated financial statements and disclosures. Compensation (Topic 718): Stock Compensation - Accounting for Share-Based Payments when the Terms of an Award Provide that a Performance Target could be achieved after the Requisite Service Period. In June 2014, ASU 2014-12 was issued which includes guidance that requires a performance target that affects vesting and that could be achieved after the requisite service period to be treated as a performance condition. This update became effective at the beginning of our 2016 fiscal year. The adoption of this ASU did not have a significant impact on our consolidated financial statements and disclosures. In addition, in March 2016, ASU 2016-09 - Stock Compensation - Improvements to Employee Share-Based Payment Accounting was issued. This ASU is intended to improve the accounting for employee share-based payments. Several aspects of the accounting for share-based payment award transactions are simplified, including: (a) income tax consequences; (b) classification of awards as either equity or liabilities; and (c) classification on the statement of cash flows. The update is effective at the beginning of our 2017 fiscal year. We have elected to early adopt this ASU and the adoption did not have a significant impact on our financial statement and disclosures. Presentation of Financial Statements - Going Concern (Subtopic 25-40): - Disclosure of Uncertainties about an Entity’s Ability to continue as a Going Concern. In August 2014, the FASB issued ASU 2014-15, requiring management to evaluate whether there is substantial doubt about the Company’s ability to continue as a going concern. This update is effective for the annual period ending after December 15, 2016, and for annual and interim periods thereafter. We have adopted this ASU and the adoption did not have a significant impact on our financial statement and disclosures. Accounting Standards Issued But Not Yet Adopted Intangibles - Goodwill and Other (Topic 350). In January 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-04. The update simplifies the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. Under the amendment an entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. This standard is effective at the beginning of our 2020 fiscal year. We are currently evaluating whether the adoption of this new guidance will have a significant impact on our consolidated financial statements and related disclosures. Business Combinations (Topic 805): Clarifying the Definition of a Business. In January 2017, ASU 2017-01 was issued. The update clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of businesses. This standard is effective at the beginning of our 2018 fiscal year. We are currently evaluating whether the adoption of this new guidance will have a significant impact on our consolidated financial statements and related disclosures. Cash Flows: Statement of Cash Flows (Topic 230) - Restricted Cash. In November 2016, ASU 2016-18 was issued. The update requires that a statement of cash flows explains the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. This standard is effective at the beginning of our 2018 fiscal year. We are currently evaluating whether the adoption of this new guidance will have a significant impact on our consolidated financial statements and related disclosures. Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other than Inventory. In October 2016, ASU 2016-16 was issued. The update prohibits the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset has been sold to an outside party. This standard is effective at the beginning of our 2018 fiscal year. We are currently evaluating whether the adoption of this new guidance will have a significant impact on our consolidated financial statements and related disclosures. Cash Flows: Statement of Cash Flows (Topic 230) - Classification of Certain Cash Receipts and Cash Payments. In August 2016 ASU 2016-15 was issued. The ASU provides guidance on classification of eight specific cash flows items. This standard is effective at the beginning of our 2018 fiscal year. We are currently evaluating whether the adoption of this new guidance will have a significant impact on our consolidated financial statements and related disclosures. Derivatives and Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments. In March 2016, ASU 2016-06 was issued. ASU 2016-06 clarifies the steps required to determine bifurcation of an embedded derivative. The update is effective at the beginning of our 2017 fiscal year. We do not believe the adoption of this new guidance will have an impact on our financial statement disclosures. Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships. In March 2016, ASU 2016-05 was issued which clarifies the change in the counterparty to a derivative instrument that has been designated as a hedging instrument does not, in and of itself, require de-designation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The update is effective at the beginning of our 2017 fiscal year. We do not believe the adoption of this new guidance will have an impact on our financial statement disclosures. Leases (Topic 842). In February 2016, ASU 2016-02, Leases, was issued. This standard will require all lessees to recognize a right of use asset and a lease liability on the balance sheet, except for leases with durations that are less than twelve months. This standard is effective at the beginning of our 2018 fiscal year. We are currently evaluating whether the adoption of this new guidance will have a significant impact on our consolidated financial statements and related disclosures. Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. In January 2016, ASU 2016-01 was issued to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The ASU supersedes the guidance to classify equity securities with readily determinable fair values into different categories, and requires equity securities (except those that are accounted for under the equity method or those that result in consolidation of the investee) to be measured at fair value with changes in the fair value recognized through net income. It also simplifies the impairment assessment of equity investments without readily determinable fair values by requiring assessment for impairment qualitatively at each reporting period. This update is effective at the beginning of our 2018 fiscal year. We are currently evaluating whether the adoption of this new guidance will have a significant impact on our consolidated financial statements and disclosures. Inventory (Topic 330): Simplifying the Measurement of Inventory. In July 2015, the FASB issued ASU 2015-11, which simplifies the subsequent measurement of inventory. The updated guidance requires that Inventory measured using any method other than LIFO or the retail inventory method (for example, inventory measured using first-in, first-out (FIFO) or average cost) be measured at the lower of cost and net realizable value. This standard is effective at the beginning of our 2017 fiscal year. We do not believe the adoption of this new guidance will have a significant impact on our consolidated financial statements and related disclosures. Revenue Recognition (Topic 606): Revenue from Contracts with Customers. In May 2014, ASU 2014-09 was issued. Under this ASU and subsequently issued amendments, an entity is required to recognize the amount of revenue it expects to be entitled to for the transfer of promised goods or services to customers. The updated standard will replace most existing revenue recognition guidance in U.S. GAAP. This ASU provides alternative methods of transition, a full retrospective and a modified restrospective approach. The modified retrospective approach would result in recognition of the cumulative impact of a retrospective application as of the beginning of the period of initial application, which in our case is the interim period beginning January 1, 2018. In preparation for adoption of the standard, we developed a cross-functional team and engaged a third-party service provider to assist us throughout our evaluation. In addition, we have factored the adoption into our ongoing ERP platform upgrade, which we previously committed to perform, as our system readiness is a key element towards the determination of the adoption approach we adopt. We continue to perform our assessment, and while those activities are not complete, we expect to identify similar performance obligations under ASC 606 as compared to those previously identified.
Estimates and Assumptions	Estimates and Assumptions The preparation of consolidated financial statements in conformity with U.S. GAAP requires us to make certain estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Accordingly, actual results could materially differ from estimated amounts. We evaluate our estimated assumptions based on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities.
Cash and Cash Equivalents	Cash and Cash Equivalents Our cash equivalents consist principally of overnight investments, bank money market accounts and bank time deposits which have an original maturity date of less than 90 days. These securities are carried at cost, which approximates market value.
Accounts Receivable and Allowance for Bad Debt	Accounts Receivable and Allowance for Bad Debt Credit extension, monitoring and collection are performed for each of our business segments. Each segment has a credit committee that is responsible for approving credit limits above certain amounts, setting and maintaining credit standards, and managing the overall quality of the credit portfolio. We perform ongoing credit evaluations of our customers and adjust credit limits based upon payment history and the customer’s current creditworthiness, as determined by our review of our customer’s credit information. We extend credit on an unsecured basis to most of our customers. Accounts receivable are deemed past due based on contractual terms agreed to with our customers. Although we analyze customers’ payment history and creditworthiness, we cannot predict with certainty that the customers to whom we extend credit will be able to remit payments on a timely basis, or at all. Because we extend credit on an unsecured basis to most of our customers, there is a possibility that any accounts receivable not collected will ultimately need to be written off. Write-offs for the year ended December 31, 2016 did not have a significant impact on our consolidated statement of operations. We continuously monitor collections and payments from our customers and maintain a provision for estimated credit losses based upon our historical experience with our customers, current market and industry conditions affecting our customers and any specific customer collection issues that we have identified. Historical payment trends may not, however, be an accurate indicator of current or future credit worthiness of our customers, particularly in difficult economic and financial markets. As a result of the limited predictability inherent in estimating which customers are less likely or unlikely to remit amounts owed to us, our provision for estimated credit losses may not be sufficient. Any write-off of accounts receivable in excess of our provision for estimated credit losses would have an adverse effect on our results of operations.
Inventories	Inventories Inventories are valued primarily using average cost, and first-in first-out in certain limited locations, and are stated at the lower of average cost or market. We utilize a variety of fuel indices and other indicators of market value. Sharp negative changes in these indices can result in reduction of our inventory valuation, which could have an adverse impact on our results of operations in the period in which we take the adjustment. Historically these adjustments have not had a significant impact on our consolidated statements of operations. Components of inventory include fuel purchase costs, the related transportation costs and changes in the estimated fair market values for inventories included in a fair value hedge relationship.
Business Combinations	Business Combinations The Company accounts for business combinations using the acquisition method of accounting, under which the purchase price of the acquisition is allocated to the assets acquired and liabilities assumed using the fair values determined by management as of the acquisition date. Contingent consideration obligations that are elements of the consideration transferred are recognized as of the acquisition date as part of the fair value transferred in exchange for the acquired business. Acquisition-related costs incurred in connection with a business combination are expensed as incurred.
Fair Value of Financial Instruments	Fair Value of Financial Instruments We measure the fair value of financial instruments using observable and unobservable inputs. Observable inputs reflect what market participants would use in pricing the instrument, based on publicly available market data obtained from sources independent of us. Unobservable inputs are inputs for which market data are not available and reflect internal market assumptions. The accounting guidance establishes the following fair value hierarchy: Level 1 Inputs - Quoted prices in active markets. Level 2 Inputs - Quoted prices for similar instruments in active markets other than quoted prices included within Level 1, quoted prices for identical or similar instruments in markets that are not active; and model based valuations whose inputs are observable. Level 3 Inputs - Inputs that are unobservable. Our policy is to recognize transfers between levels as of the beginning of the reporting period in which the event or change in circumstance caused the transfer to occur.
Derivatives	Derivatives We enter into financial derivative contracts to mitigate the risk of market price fluctuations in aviation, marine and land fuel, to offer our customers fuel pricing alternatives to meet their needs and to mitigate the risk due to changes in foreign currency exchange rates. While we currently believe that our derivative contracts will be effective in mitigating the associated price risks, it is possible that our derivative instruments will be ineffective at mitigating material changes in prices, which could have an adverse impact on our financial position and results of operations. At the inception and on an ongoing basis, we assess the hedging relationship to determine its effectiveness in offsetting changes in cash flows or fair value attributable to the hedged risk. The fair value of our derivatives is derived using observable and certain unobservable inputs, such as basis differentials, which are based on the difference between the historical prices of our prior transactions and the underlying observable data. Measurement of the fair value of our derivatives also requires the assessment of certain risks related to non-performance, which requires a significant amount of judgment. The effect on our income before income taxes of a 10% change in the model input for non-performance risk would not be significant to our consolidated statements of operations. We have applied the normal purchase and normal sales exception (“NPNS”), as provided by accounting guidance for derivative instruments and hedging activities, to certain of our physical forward sales and purchase contracts. While these contracts are considered derivative instruments under the guidance for derivative instruments and hedging activities, they are not recorded at fair value, but rather are recorded in our consolidated financial statements when physical settlement of the contracts occurs. If it is determined that a transaction designated as NPNS no longer meets the scope of the exception, the fair value of the related contract is recognized as an asset or liability on the consolidated balance sheets and the changes in the the fair value of the contract is immediately recognized through earnings. Our derivative contracts are subject to the accounting guidance for derivative instruments and recognized at their estimated fair market value in accordance with the accounting guidance for fair value measurements. If the derivative instrument is not designated as a hedge, changes in the estimated fair market value are recognized as a component of revenue, cost of revenue or other income (expense), net (based on the underlying transaction type) in the consolidated statements of income and comprehensive income. Derivatives which qualify for hedge accounting may be designated as either a fair value or cash flow hedge. For our fair value hedges, changes in the estimated fair market value of the hedging instrument and the hedged item are recognized in the same line item as a component of either revenue or cost of revenue (based on the underlying transaction type) in the consolidated statements of income and comprehensive income. For our cash flow hedges, the effective portion of the changes in the fair market value of the hedging instrument is initially recognized as a component of other comprehensive income in the shareholders’ equity section of the consolidated balance sheets and subsequently reclassified into the same line item as the underlying forecasted transaction when both are settled or deemed probable of not occurring. The ineffective portion of the changes in the estimated fair market value of the hedging instrument is recognized in the same line item as a component of either revenue or cost of revenue (based on the underlying transaction type) in the consolidated statements of income and comprehensive income. Cash flows for our hedging instruments used in our hedges are classified in the same category as the cash flow from the hedged items. If for any reason hedge accounting is discontinued, then any cash flows subsequent to the date of discontinuance will be classified in a manner consistent with the nature of the instrument. To qualify for hedge accounting, the hedging relationship between the hedging instruments and hedged items must be expected to be highly effective in achieving offsetting changes in the fair values or cash flows attributable to the hedged risk at the inception of the hedge. We use a regression analysis based on historical spot prices in assessing the qualification for our fair value and cash flow hedges. However, our measurement of hedge ineffectiveness for our fair value inventory hedges utilizes spot prices for the hedged item (inventory) and forward or futures prices for the hedging instrument. Hedge ineffectiveness measurement for our cash flow hedges is based on forward or futures prices for the hedged item and hedging instrument. Any excluded component (changes in the difference between the spot price and the forward or futures price) , along with ineffectiveness, is included as a component of revenue or cost of revenue in earnings. Adjustments to the carrying amounts of hedged items in a fair value hedge relationship are discontinued in instances where the related hedging instrument is deemed no longer highly effective in achieving offsetting changes in fair value. Therefore, any previously recorded fair market value changes are not adjusted until the fuel is sold.
Property and Equipment	Property and Equipment Property and equipment are carried at cost less accumulated depreciation and amortization. Depreciation and amortization are calculated using the straight‑line method over the estimated useful lives of the assets. Costs of major additions and improvements are capitalized while expenditures for maintenance and repairs, which do not extend the life of the asset, are expensed. Upon sale or disposition of property and equipment, the cost and related accumulated depreciation and amortization are eliminated from the accounts and any resulting gain or loss is credited or charged to income. Long‑lived assets held and used by us are reviewed based on market factors and operational considerations for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Purchases of computer software are capitalized. External costs and certain internal costs directly associated with developing significant computer software applications for internal use are capitalized. Computer software costs are amortized using the straight‑line method over the estimated useful life of the software.
Goodwill and Identifiable Intangible Assets	Goodwill and Identifiable Intangible Assets Goodwill arises because the purchase price paid reflects numerous factors, including the strategic fit and expected synergies these acquisitions bring to our existing operations. Goodwill is recorded at fair value and is reviewed at least annually at year-end (or more frequently under certain circumstances) for impairment. Goodwill is evaluated for impairment during the fourth quarter of each year based on an assessment of qualitative factors to determine whether it is more likely than not that the fair value of any individual reporting unit is less than its carrying amount (Step 0). If we determine that it is more likely than not that the fair value of a reporting unit is greater than its carrying value, then no further testing is required. Otherwise, we would perform the two-step impairment analysis described below. Step 1 requires us to compare the fair value of the reporting units to which goodwill was assigned to their respective carrying values. In calculating fair value, we use the income approach as our primary indicator of fair value. Under the income approach, we calculate the fair value of a reporting unit based on the present value of estimated future cash flows. These estimates are based on a number of factors including industry experience, business expectations and the economic environment. If the fair value exceeds the carrying value, no further work is required and no impairment loss is recognized. If the carrying value exceeds the fair value, the goodwill of the reporting unit is potentially impaired and the Company would then complete step 2 in order to measure the impairment loss. The performance of the annual fiscal 2016 impairment analysis did not result in an impairment of the Company's goodwill. The qualitative assessment associated with step 0 and the quantitative assessment associated with step 1 of our goodwill impairment analysis both involve significant management estimates and judgment in order to properly determine that the factors assessed are appropriate and are accurate for each of the Company’s reporting units. In connection with our acquisitions, we record identifiable intangible assets at fair value. The determination of the fair values of our identifiable intangible assets involves a significant amount of forecasting and other assumptions associated with recently acquired businesses for which we may not have as much historical information or trend data as we would for our existing businesses. Identifiable intangible assets subject to amortization are amortized over their estimated useful lives and are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. We assess identifiable intangible assets not subject to amortization during the fourth quarter of each year for potential impairment. Our impairment analysis of our intangible assets not subject to amortization (primarily trademarks and/or trade names) generally involves the use of qualitative and quantitative analyses to estimate whether the estimated future cash flows generated as a result of these assets will be greater than or equal to the carrying value assigned to such assets.
Other Investments	Other Investments Our other investments consist primarily of equity investments, net of basis adjustments. These investments are accounted for under the equity method as we own less than 50 percent of the entities and exercise significant influence over the investee, but do not have operational or financial control.
Revenue Recognition	Revenue Recognition Revenue from the sale of fuel is recognized when the sales price is fixed or determinable, collectability is reasonably assured and title passes to the customer, which is when the delivery of fuel is made to our customer directly from us, the supplier or a third‑party subcontractor. Our fuel sales are generated as a fuel reseller as well as from on‑hand inventory supply. When acting as a fuel reseller, we generally purchase fuel from the supplier, and contemporaneously resell the fuel to the customer, normally taking delivery for purchased fuel at the same place and time as the delivery is made to the customer. We record the gross sale of the fuel as we generally take inventory risk, have latitude in establishing the sales price, have discretion in the supplier selection, maintain credit risk and are the primary obligor in the sales arrangement. Revenue from fuel‑related services is recognized when services are performed, the sales price is fixed or determinable and collectability is reasonably assured. We record the sale of fuel‑related services on a gross basis as we generally have latitude in establishing the sales price, have discretion in supplier selection, maintain credit risk and are the primary obligor in the sales arrangement. Commission from fuel broker services is recognized when services are performed and collectability is reasonably assured. When acting as a fuel broker, we are paid a commission by the supplier. Revenue from card payment and processing transactions is recognized at the time the purchase is made by the customer using the charge card. Whether the services have been performed and when title and risk of loss passes to the customer are the factors we take into consideration in deciding when to recognize revenue. These factors are readily determinable and consistently applied throughout our business. Therefore, we generally have not needed to make significant estimates or assumptions with respect to revenue recognition.
Share-Based Payment Awards	Share‑Based Payment Awards We account for share‑based payment awards on a fair value basis. Under fair value accounting, the grant‑date fair value of the share‑based payment award is amortized as compensation expense, on a straight‑line basis, over the vesting period for both graded and cliff vesting awards. Annual compensation expense for share‑based payment awards is reduced by an expected forfeiture amount on outstanding share‑based payment awards. We utilize our historical forfeiture rates to calculate future expected forfeitures. These estimates can vary significantly from actual forfeiture rates experienced. Our estimated forfeiture rates have historically approximated actual forfeitures. The estimated fair value of stock awards, such as restricted stock and restricted stock units (“RSUs”) is based on the grant‑date market value of our common stock, as defined in the respective plans under which the awards were granted. To determine the estimated fair value of stock‑settled stock appreciation rights (“SSAR Awards”), we use the Black‑Scholes option pricing model. The estimation of the fair value of SSAR Awards on the date of grant using an option‑pricing model is affected by our stock price as well as assumptions regarding a number of complex and subjective variables. These variables include our expected stock price volatility over the term of the awards, actual and projected employee stock option exercise behaviors, risk‑ free interest rates and expected dividends. The expected term of SSAR Awards represents the estimated period of time from grant until exercise or conversion and is based on vesting schedules and expected post‑vesting, exercise and employment termination behavior. Expected volatility is based on the historical volatility of our common stock over the period that is equivalent to the award’s expected life. Any adjustment to the historical volatility as an indicator of future volatility would be based on the impact to historical volatility of significant non‑recurring events that would not be expected in the future. Risk‑free interest rates are based on the U.S. Treasury yield curve at the time of grant for the period that is equivalent to the award’s expected life. Dividend yields are based on the historical dividends of World Fuel over the period that is equivalent to the award’s expected life, as adjusted for stock splits. We have elected to early adopt ASU 2016-09 - Stock Compensation - Improvements to Employee Share-Based Payment Accounting. As required by ASU 2016.09, cash flows from income tax benefits resulting from income tax deductions in excess of the compensation cost recognized for share‑based payment awards (excess income tax benefits) are classified as operating cash flows.
Foreign Currency	Foreign Currency The functional currency of our U.S. and foreign subsidiaries is the U.S. dollar, except for certain subsidiaries which utilize their respective local currency as their functional currency. Foreign currency transaction gains and losses are recognized upon settlement of foreign currency transactions. In addition, for unsettled foreign currency transactions, foreign currency translation gains and losses are recognized for changes between the transaction exchange rates and month‑end exchange rates. Foreign currency transaction gains and losses are included in other income (expense), net, in the accompanying consolidated statements of income and comprehensive income in the period incurred. Revenues and expenses of the subsidiaries that have a functional currency other than the U.S. dollar have been translated into U.S. dollars at average exchange rates prevailing during the period. The assets and liabilities of these subsidiaries have been translated at the rates of exchange on the balance sheet dates. The resulting translation gain and loss adjustments are recorded in accumulated other comprehensive income as a separate component of shareholders’ equity.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, and operating loss and income tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted income tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in income tax rates is recognized in the income tax provision in the period that includes the enactment date. We must assess the likelihood that our deferred tax assets will be recovered from our future taxable income, and to the extent we believe that recovery is not likely, we must establish a valuation allowance against those deferred tax assets. Deferred tax liabilities generally represent items for which we have already taken a deduction in our income tax return, but we have not yet recognized the items as expenses in our results of operations. Significant judgment is required in evaluating our tax positions, and in determining our provisions for income taxes, our deferred tax assets and liabilities and any valuation allowance recorded against our net deferred tax assets. We establish reserves when, despite our belief that the income tax return positions are fully supportable, certain positions are likely to be challenged and we may ultimately not prevail in defending those positions. U.S. income taxes have not been recognized on undistributed earnings of foreign subsidiaries. Our intention is to reinvest these earnings permanently in active non-U.S. business operations. Therefore, no income tax liability has been accrued for these earnings. Because of the availability of U.S. foreign tax credits, it is not practicable to determine the amount of U.S. income tax payable if such earnings are not reinvested indefinitely.
Earnings per Common Share	Earnings per Common Share Basic earnings per common share is computed by dividing net income attributable to World Fuel and available to common shareholders by the sum of the weighted average number of shares of common stock, stock units, restricted stock entitled to dividends not subject to forfeiture and vested RSUs outstanding during the period. Diluted earnings per common share is computed by dividing net income attributable to World Fuel and available to common shareholders by the sum of the weighted average number of shares of common stock, stock units, restricted stock entitled to dividends not subject to forfeiture and vested RSUs outstanding during the period and the number of additional shares of common stock that would have been outstanding if our outstanding potentially dilutive securities had been issued. Potentially dilutive securities include restricted stock subject to forfeitable dividends, non‑vested RSUs and SSAR Awards. The dilutive effect of potentially dilutive securities is reflected in diluted earnings per common share by application of the treasury stock method. Under the treasury stock method, an increase in the fair market value of our common stock can result in a greater dilutive effect from potentially dilutive securities.