Business acquisition earn out payables.

No definition available.

Name:	bro_BusinessAcquisitionEarnOutPayables
Namespace Prefix:	bro_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Business acquisition purchase price allocation goodwill expected tax nondeductible amount.

+ References

No definition available.

+ Details

Name:	bro_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxNondeductibleAmount
Namespace Prefix:	bro_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Business acquisitions purchase price allocation adjustment purchase price.

+ References

No definition available.

+ Details

Name:	bro_BusinessAcquisitionsPurchasePriceAllocationAdjustmentPurchasePrice
Namespace Prefix:	bro_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Business combination consideration.

+ References

No definition available.

+ Details

Name:	bro_BusinessCombinationConsideration
Namespace Prefix:	bro_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Business combination pro forma information income (loss) before income taxes of acquire since acquisition date actual.

+ References

No definition available.

+ Details

Name:	bro_BusinessCombinationProFormaInformationIncomeLossBeforeIncomeTaxesOfAcquireSinceAcquisitionDateActual
Namespace Prefix:	bro_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Earn out payable not deductible until earned paid

+ References

No definition available.

+ Details

Name:	bro_EarnOutPayableNotDeductibleUntilEarnedPaid
Namespace Prefix:	bro_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Goodwill adjustment and acquired net.

+ References

No definition available.

+ Details

Name:	bro_GoodwillAdjustmentAndAcquiredNet
Namespace Prefix:	bro_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Maximum Future Contingency Payments Acquisitions

+ References

No definition available.

+ Details

Name:	bro_MaximumFutureContingencyPaymentsAcquisitions
Namespace Prefix:	bro_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482665/350-30-50-1

+ Details

Name:	us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479907/805-20-50-5

+ Details

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479581/805-30-50-1

+ Details

Name:	us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479581/805-30-50-1

+ Details

Name:	us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479328/805-10-50-2

+ Details

Name:	us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 55
-Paragraph 37
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479303/805-10-55-37

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479907/805-20-50-1

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_GoodwillFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 25
-Paragraph 16
-SubTopic 10
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479405/805-10-25-16

+ Details

Name:	us-gaap_GoodwillPurchaseAccountingAdjustments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The number of businesses acquired by the entity during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfBusinessesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- 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
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479581/805-30-50-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-13

+ Details

Name:	us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ExtinguishmentOfDebtAxis=us-gaap_AccountsPayableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bro_RetailSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bro_NationalProgramsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bro_WholesaleBrokerageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CustomerRelationshipsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_NoncompeteAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=bro_OtherAcquisitionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=bro_GrpHoldcoLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Business Combinations - Additional Information (Details) $ in Millions		9 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2023 USD ($) Acquisition	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Business Acquisition [Line Items]
Number of acquisitions \| Acquisition		21
Purchase price of acquisitions		$ 10.9
Increase (decrease) in goodwill		(9.7)
Payments to Acquire Businesses, Gross	$ 2.9	176.8
Net assets acquired	233.0	233.0
Total consideration	233.0	233.0
Goodwill	154.2	154.2
Goodwill currently deductible for income tax purposes	35.0	35.0
Goodwill currently non-deductible for income tax purposes	107.0	107.0
Goodwill related to the recorded earn-out payables	12.2	12.2
Total revenues related to acquisitions		17.6
Income before income taxes related to acquisitions		5.3
Estimated acquisition earn-out payables	258.2	258.2	$ 231.5	$ 251.7	$ 249.9	$ 232.9	$ 291.0
Maximum Future Contingency payments Acquisitions	550.5	550.5
Other Noncurrent Liabilities
Business Acquisition [Line Items]
Estimated acquisition earn-out payables			$ 89.5
Accounts payable
Business Acquisition [Line Items]
Estimated acquisition earn-out payables	168.7	168.7
Retail
Business Acquisition [Line Items]
Increase (decrease) in goodwill		15.5
Goodwill net		154.0
National Programs
Business Acquisition [Line Items]
Increase (decrease) in goodwill		(23.5)
Goodwill net		(21.1)
Wholesale Brokerage
Business Acquisition [Line Items]
Increase (decrease) in goodwill		(1.7)
Goodwill net		$ 21.2
Purchased Customer Accounts
Business Acquisition [Line Items]
Weighted average life (years)		14 years 9 months 18 days
Non-compete Agreements
Business Acquisition [Line Items]
Weighted average life (years)		4 years 4 months 24 days
Other Acquisitions
Business Acquisition [Line Items]
Net assets acquired	233.0	$ 233.0
Total consideration	233.0	233.0
Goodwill	154.2	154.2
Other Acquisitions \| Maximum
Business Acquisition [Line Items]
Total consideration	50.0	50.0
GRP Holdco Limited
Business Acquisition [Line Items]
Maximum potential earn-out amount	$ 0.0	$ 0.0