Debt Instruments Maturity Year

No definition available.

Name:	bro_DebtInstrumentsMaturityYear
Namespace Prefix:	bro_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Period remaining on line of credit facility before it terminates, 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_LineOfCreditFacilityExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Long-Term Debt - Long-Term Debt Instrument (Additional Information) (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015	Sep. 18, 2014	May 20, 2014	Apr. 16, 2014	Apr. 15, 2014	Jul. 01, 2013
Debt Instrument [Line Items]
Long-term Line of Credit	$ 453,750,000	$ 481,250,000			$ 25,000,000.0
Credit Agreement [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	$ 508,800,000	$ 529,400,000
5.660% senior notes, Series C, semi-annual interest payments, balloon due 2016
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	5.66%	5.66%
Debt instrument maturity year	2016	2016
4.500% senior notes, Series E, quarterly interest payments, balloon due 2018
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	4.50%	4.50%
Debt instrument maturity year	2018	2018
4.200% senior notes, semi-annual interest payments, balloon due 2024
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	4.20%	4.20%
Debt instrument maturity year	2024	2024
Five Year Term Loan Facility Expires In Two Thousand Twenty-Two [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	$ 453,750,000	$ 481,250,000
Line of credit facility, expiration period	5 years	5 years
Line of credit facility, expiration date	May 20, 2019	May 20, 2019
Five Year Term Loan Facility Expires In Two Thousand Twenty-Two [Member] \| LIBOR
Debt Instrument [Line Items]
Debt instrument, variable interest rate	1.75%	1.75%
Five Year Term Loan Facility Expires In Two Thousand Ninteen Current [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	0.20%	0.20%
Debt instrument maturity year	2019	2019
5-year revolving-loan facility, periodic interest payments, currently LIBOR plus up to 1.50%, plus commitment fees up to 0.25%, expires May 20, 2019
Debt Instrument [Line Items]
Long-term Line of Credit	$ 0	$ 0
Line of credit facility, expiration period	5 years	5 years
Line of credit facility, commitment fee percentage	0.25%	0.25%
Line of credit facility, expiration date	May 20, 2019	May 20, 2019
5-year revolving-loan facility, periodic interest payments, currently LIBOR plus up to 1.50%, plus commitment fees up to 0.25%, expires May 20, 2019 \| LIBOR
Debt Instrument [Line Items]
Debt instrument, variable interest rate	1.50%	1.50%
Revolving credit loan, quarterly interest payments, LIBOR plus up to 1.40% and availability fee up to 0.25%, expires December 31, 2016
Debt Instrument [Line Items]
Long-term Line of Credit	$ 0
Line of credit facility, expiration date	Dec. 31, 2016	Dec. 31, 2016
Maximum \| Revolving credit loan, quarterly interest payments, LIBOR plus up to 1.40% and availability fee up to 0.25%, expires December 31, 2016
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage	0.25%	0.25%
Maximum \| Revolving credit loan, quarterly interest payments, LIBOR plus up to 1.40% and availability fee up to 0.25%, expires December 31, 2016 \| LIBOR
Debt Instrument [Line Items]
Debt instrument, variable interest rate	1.40%	1.40%
Wells Fargo [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	$ 800,000,000	$ 800,000,000
Beecher [Member] \| Wells Fargo [Member]
Debt Instrument [Line Items]
Long-term Line of Credit						$ 50,000,000.0	$ 50,000,000.0
Uncommitted Facility [Member] \| New Master Agreement [Member]
Debt Instrument [Line Items]
Long-term Line of Credit		$ 0
Term Loan [Member]
Debt Instrument [Line Items]
Long-term Line of Credit				$ 550,000,000.0
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Line of Credit			$ 475,000,000	$ 375,000,000
Revolving Credit Facility [Member] \| Maximum \| LIBOR
Debt Instrument [Line Items]
Debt instrument, variable interest rate	1.50%