Income Taxes - Reconciliation of Provision for Income Taxes with Federal Statutory Income Tax Rate (Detail) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
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Dec. 31, 2014
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Dec. 31, 2013
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Dec. 31, 2012
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Income Tax Disclosure [Abstract] | |||
Federal statutory rate | $ 93.6us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate | $ 96.1us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate | $ 85.9us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate |
State income taxes - net of Federal benefit | 12.0us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes | 6.5us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes | 9.4us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes |
Foreign taxes | 0.8us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential | (0.8)us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential | 0.9us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential |
Alternative energy, foreign and other tax credits | (145.5)us-gaap_IncomeTaxReconciliationTaxCredits | (93.8)us-gaap_IncomeTaxReconciliationTaxCredits | (45.3)us-gaap_IncomeTaxReconciliationTaxCredits |
Foreign dividends and other permanent differences | (6.1)ajg_IncomeTaxReconciliationForeignDividendsAndOtherPermanentDifferences | (2.5)ajg_IncomeTaxReconciliationForeignDividendsAndOtherPermanentDifferences | (2.7)ajg_IncomeTaxReconciliationForeignDividendsAndOtherPermanentDifferences |
Nondeductible employee compensation | 5.4us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost | ||
Changes in unrecognized tax benefits | 2.4ajg_IncomeTaxReconciliationChangesInUnrecognizedTaxBenefitsRelatedToResolutionOfFederalAndStateAuditsExpirationOfVariousStatutesOfLimitationsAndOtherItems | 1.5ajg_IncomeTaxReconciliationChangesInUnrecognizedTaxBenefitsRelatedToResolutionOfFederalAndStateAuditsExpirationOfVariousStatutesOfLimitationsAndOtherItems | 0.6ajg_IncomeTaxReconciliationChangesInUnrecognizedTaxBenefitsRelatedToResolutionOfFederalAndStateAuditsExpirationOfVariousStatutesOfLimitationsAndOtherItems |
Change in valuation allowance | 0.5us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance | 0.3us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance | |
Other | 1.4us-gaap_IncomeTaxReconciliationOtherAdjustments | (1.6)us-gaap_IncomeTaxReconciliationOtherAdjustments | 1.2us-gaap_IncomeTaxReconciliationOtherAdjustments |
Provision (benefit) for income taxes | $ (36.0)us-gaap_IncomeTaxExpenseBenefit | $ 5.9us-gaap_IncomeTaxExpenseBenefit | $ 50.3us-gaap_IncomeTaxExpenseBenefit |
Federal statutory rate, % of Pretax Earnings | 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate | 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate | 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate |
State income taxes-net of Federal benefit, % of Pretax Earnings | 4.50%us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes | 2.40%us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes | 3.80%us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes |
Foreign taxes, % of Pretax Earnings | 0.30%us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential | (0.30%)us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential | 0.40%us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential |
Alternative energy, foreign and other tax credits, % of Pretax Earnings | (54.40%)us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits | (34.20%)us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits | (18.50%)us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits |
Foreign dividends and other permanent differences, % of Pretax Earnings | (2.30%)ajg_EffectiveIncomeTaxRateReconciliationForeignDividendsAndOtherPermanentDifferences | (0.90%)ajg_EffectiveIncomeTaxRateReconciliationForeignDividendsAndOtherPermanentDifferences | (1.10%)ajg_EffectiveIncomeTaxRateReconciliationForeignDividendsAndOtherPermanentDifferences |
Nondeductible employee compensation, % of Pretax Earnings | 2.00%us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost | ||
Changes in unrecognized tax benefits, % of Pretax Earnings | 0.90%ajg_EffectiveIncomeTaxRateReconciliationChangesInUnrecognizedTaxBenefitsRelatedToResolutionOfFederalAndStateAuditsExpirationOfVariousStatutesOfLimitationsAndOtherItems | 0.50%ajg_EffectiveIncomeTaxRateReconciliationChangesInUnrecognizedTaxBenefitsRelatedToResolutionOfFederalAndStateAuditsExpirationOfVariousStatutesOfLimitationsAndOtherItems | 0.20%ajg_EffectiveIncomeTaxRateReconciliationChangesInUnrecognizedTaxBenefitsRelatedToResolutionOfFederalAndStateAuditsExpirationOfVariousStatutesOfLimitationsAndOtherItems |
Change in valuation allowance, % of Pretax Earnings | 0.20%us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance | 0.10%us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance | |
Other, % of Pretax Earnings | 0.50%us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments | (0.60%)us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments | 0.60%us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments |
Total provision (benefit) for income taxes-continuing operations, % of Pretax Earnings | (13.50%)us-gaap_EffectiveIncomeTaxRateContinuingOperations | 2.10%us-gaap_EffectiveIncomeTaxRateContinuingOperations | 20.50%us-gaap_EffectiveIncomeTaxRateContinuingOperations |
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- Definition
Effective income tax rate reconciliation, Changes in unrecognized tax benefits related to resolution of Federal and state audits, expiration of various statutes of limitations and other items No definition available.
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Effective income tax rate reconciliation, Foreign dividends and other permanent differences No definition available.
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- Definition
Income tax reconciliation, Changes in unrecognized tax benefits related to resolution of Federal and state audits, expiration of various statutes of limitations and other items. No definition available.
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- Definition
Income tax reconciliation, foreign dividends and other permanent differences No definition available.
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- Definition
Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Percentage of domestic federal statutory tax rate applicable to pretax income (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Percentage 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 changes in the valuation allowance for deferred tax assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Percentage 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 applicable to statutory income tax expense (benefit) outside of the country of domicile. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Percentage 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 equity-based compensation costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Percentage 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 other adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Percentage 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 applicable to state and local income tax expense (benefit), net of federal tax expense (benefit). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Percentage 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 tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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 foreign income tax expense (benefit). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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 nondeductible equity-based compensation costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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 other adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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 state and local income tax expense (benefit). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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 tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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