XML 75 R63.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Derivatives and Hedging Activity - Summary of Amounts of Derivative Gains (Losses) Recognized In Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2017 | Mar. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative gains (losses) recognized in accumulated other comprehensive loss | $ 6.2 | $ (2.3)
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion) | (2.4) | (1.2)
Interest Rate Contracts [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative gains (losses) recognized in accumulated other comprehensive loss | 0.8 | 1.1
Foreign Exchange Contracts [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative gains (losses) recognized in accumulated other comprehensive loss | 5.4 | (3.4)
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion) | (2.4) | (1.2)
Commission Revenue [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative gains (losses) recognized in accumulated other comprehensive loss | 2.4 | (3.4)
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion) | (2.8) | (1.2)
Commission Revenue [Member] | Foreign Exchange Contracts [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative gains (losses) recognized in accumulated other comprehensive loss | 2.4 | (3.4)
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion) | (2.8) | (1.2)
Compensation Expense [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative gains (losses) recognized in accumulated other comprehensive loss | 1.8 |
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion) | 0.2 |
Compensation Expense [Member] | Foreign Exchange Contracts [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative gains (losses) recognized in accumulated other comprehensive loss | 1.8 |
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion) | 0.2 |
Operating Expense [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative gains (losses) recognized in accumulated other comprehensive loss | 1.2 |
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion) | 0.2 |
Operating Expense [Member] | Foreign Exchange Contracts [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative gains (losses) recognized in accumulated other comprehensive loss | 1.2 |
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion) | 0.2 |
Interest Expense [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative gains (losses) recognized in accumulated other comprehensive loss | 0.8 | 1.1
Interest Expense [Member] | Interest Rate Contracts [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative gains (losses) recognized in accumulated other comprehensive loss | $ 0.8 | $ 1.1

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_DerivativeInstrumentsGainLossLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4D -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624177-113959 + Details
Name: | us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=ajg_CommissionRevenueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=ajg_CompensationExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_OperatingExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_InterestExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |