XML 65 R55.htm IDEA: XBRL DOCUMENT
v3.23.1

Credit and Other Debt Agreements - Additional Information (Detail) - USD ($) $ in Millions | Mar. 02, 2023 | Mar. 31, 2023 | Dec. 31, 2022
--- | --- | --- | ---
Fixed Rate of 5.75%, Balloon Due March 2, 2053 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Periodic payment of interest |  | 5.75% | 5.75%
Unsecured Senior Notes [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Notes issued and sold | $ 950.0 |  |
Weighted average interest rate | 5.05% |  |
Realized a cash gain (loss) on hedging transaction | $ 112.7 |  |
Derivative instrument, term | 10 years |  |
Unsecured Senior Notes [Member] | Fixed Rate of 5.50%, Balloon Due May 2, 2033 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Notes issued and sold | $ 350.0 |  |
Periodic payment of interest | 5.50% |  |
Periodic payments of interest and principal, expiry year | 2033 |  |
Unsecured Senior Notes [Member] | Fixed Rate of 5.75%, Balloon Due March 2, 2053 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Notes issued and sold | $ 600.0 |  |
Periodic payment of interest | 5.75% |  |
Periodic payments of interest and principal, expiry year | 2053 |  |

X
- Definition Debt Instrument Maturity Year + References No definition available. + Details
Name: | ajg_DebtInstrumentMaturityYear
Namespace Prefix: | ajg_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Weighted average interest rate of debt outstanding. + References No definition available. + Details
Name: | us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DerivativeTermOfContract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5618551-113959 + Details
Name: | us-gaap_GainLossOnDerivativeInstrumentsNetPretax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The fair value of notes issued in noncash investing and financing activities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=126999549&loc=d3e4313-108586 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=126999549&loc=d3e4332-108586 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=126999549&loc=d3e4304-108586 + Details
Name: | us-gaap_NotesIssued1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_ExtinguishmentOfDebtAxis=ajg_FixedRateOfFivePointSevenFivePercentBalloonDueMarchTwoTwoThousandFiftyThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=ajg_SeniorUnsecuredNoteMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ExtinguishmentOfDebtAxis=ajg_FixedRateOfFivePointFiveZeroPercentBalloonDueMayTwoTwoThousandThirtyThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |