XML 50 R40.htm IDEA: XBRL DOCUMENT
v3.22.1

Business Combinations - Acquisition Method for Recording Business Combinations (Detail) | 3 Months Ended
--- | ---
Mar. 31, 2022 USD ($)
Devitt Insurance Services Ltd [Member] |
Business Acquisition [Line Items] |
Cash Paid | $ 73,600,000
Accrued Liability | 1,300,000
Escrow Deposited | 3,400,000
Recorded Earnout Payable | 12,500,000
Total Recorded Purchase Price | 90,800,000
Maximum Potential Earnout Payable | 12,500,000
Four Other Acquisitions [Member] |
Business Acquisition [Line Items] |
Cash Paid | 16,300,000
Accrued Liability | 2,400,000
Escrow Deposited | 700,000
Recorded Earnout Payable | 4,200,000
Total Recorded Purchase Price | 23,600,000
Maximum Potential Earnout Payable | 8,400,000
2022 Acquisitions [Member] |
Business Acquisition [Line Items] |
Cash Paid | 89,900,000
Accrued Liability | 3,700,000
Escrow Deposited | 4,100,000
Recorded Earnout Payable | 16,700,000
Total Recorded Purchase Price | 114,400,000
Maximum Potential Earnout Payable | $ 20,900,000

X
- Definition Business Acquisition Cost Of Acquired Entity Purchase Price Net + References No definition available. + Details
Name: | ajg_BusinessAcquisitionCostOfAcquiredEntityPurchasePriceNet
Namespace Prefix: | ajg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Business combination recognized identifiable assets acquired and liabilities accrued liability. + References No definition available. + Details
Name: | ajg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAccruedLiability
Namespace Prefix: | ajg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Maximum Potential Earnout Payable + References No definition available. + Details
Name: | ajg_MaximumPotentialEarnoutPayable
Namespace Prefix: | ajg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Recorded Earnout Payable + References No definition available. + Details
Name: | ajg_RecordedEarnOutPayable
Namespace Prefix: | ajg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes and insurance obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. This element excludes replacement reserves which are an escrow separately provided for within the US GAAP taxonomy. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.10) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 954 -SubTopic 440 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6491277&loc=d3e6429-115629 + Details
Name: | us-gaap_EscrowDeposit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=ajg_DevittInsuranceServicesLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=ajg_FourOtherAcquisitionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=ajg_TwoThousandTwentyTwoAcquisitionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |