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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Represents the aggregate of total long-term debt, including current maturities and short-term debt.

No definition available.

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

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Fair value of the amount outstanding under the credit facility.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Data Type:	xbrli:monetaryItemType
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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Namespace Prefix:
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Name:	us-gaap_DebtInstrumentAxis=int_LettersOfCreditAndBankersAcceptanceMember
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Name:	us-gaap_DebtInstrumentAxis=int_AmendedCreditFacilityMember
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Data Type:	na
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