XML 57 R46.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Income Taxes (Details) $ in Millions, ₩ in Billions | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2018 USD ($) | Sep. 30, 2017 USD ($) | Sep. 30, 2018 USD ($) | Sep. 30, 2017 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2017 KRW (₩)
Income tax provision | $ 23.0 | $ 82.6 | $ 42.7 | $ 92.2 |  |
Effective income tax rate | 37.30% | 185.00% | 30.10% | 79.80% |  |
Income tax expense, adjustments for ASU 2016-09, adjustment pursuant to SAB-118, and changes in valuation allowance | $ 1.5 |  |  |  |  |
Effective income tax rate reconciliation, valuation allowance on U.S. deferred tax assets |  | $ 76.9 |  | $ 76.9 |  |
Income tax expense, uncertain tax positions |  | 1.7 |  |  |  |
Income tax benefit, adjustment pursuant to SAB-118, uncertain tax positions, adjustments for ASU 2016-09, and changes in valuation allowance |  |  | $ 7.4 |  |  |
Income tax expense due to change in estimate related to uncertain tax position and adjustment for ASU 2016-09 |  |  |  | $ 5.6 |  |
Tax Authority, South Korea (SRTO) |  |  |  |  |  |
Income tax assessment notice, amount |  |  |  |  | $ 10.2 | ₩ 11.3
2017 |  |  |  |  |  |
Effective income tax rate reconciliation, valuation allowance on U.S. deferred tax assets |  | 24.0 |  |  |  |
2016 and previous |  |  |  |  |  |
Effective income tax rate reconciliation, valuation allowance on U.S. deferred tax assets |  | $ 52.9 |  |  |  |
Without income tax benefit adjustment and valuation allowance |  |  |  |  |  |
Effective income tax rate | 34.90% | 12.50% | 35.30% | 8.30% |  |

X
- Definition Effective Income Tax Rate Reconciliation, Share-Based Compensation, Excess Tax Benefit, Change In Deferred Tax Assets Valuation Allowance, And Tax Cuts And Jobs Act + References No definition available. + Details
Name: | int_EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitChangeInDeferredTaxAssetsValuationAllowanceAndTaxCutsAndJobsAct
Namespace Prefix: | int_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Effective Income Tax Rate Reconciliation, Tax Contingencies And Share-Based Compensation, Excess Tax Benefit, Amount + References No definition available. + Details
Name: | int_EffectiveIncomeTaxRateReconciliationTaxContingenciesAndShareBasedCompensationExcessTaxBenefitAmount
Namespace Prefix: | int_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Effective Income Tax Rate Reconciliation, Tax Contingency, Share-Based Compensation, Excess Tax Benefit, Change In Deferred Tax Assets Valuation Allowance, And Tax Cuts And Jobs Act + References No definition available. + Details
Name: | int_EffectiveIncomeTaxRateReconciliationTaxContingencyShareBasedCompensationExcessTaxBenefitChangeInDeferredTaxAssetsValuationAllowanceAndTaxCutsAndJobsAct
Namespace Prefix: | int_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)(2)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319 + Details
Name: | us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of estimated penalties recognized in the period arising from income tax examinations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
Name: | us-gaap_IncomeTaxExaminationPenaltiesExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(h)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 20 -Section 45 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109238882&loc=d3e38679-109324 + Details
Name: | us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=84176650&loc=d3e32123-109318 + Details
Name: | us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in income tax contingencies. Including, but not limited to, domestic tax contingency, foreign tax contingency, state and local tax contingency, and other contingencies. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319 + Details
Name: | us-gaap_IncomeTaxReconciliationTaxContingencies
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=int_TaxAuthoritySouthKoreaSRTOMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxPeriodAxis=us-gaap_TaxYear2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxPeriodAxis=int_TaxYear2016AndPreviousMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_ProFormaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |