Investments - Summary of Investments (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Investments Debt And Equity Securities [Abstract]
Certificates of deposit, U.S. Treasury securities and obligations of U.S. Government agencies, Corporate debt and other securities,Current	$ 12,300	$ 10,624
Certificates of deposit, U.S. Treasury securities and obligations of U.S. Government agencies, Corporate debt and other securities,Non-Current	$ 19,021	$ 16

certificates of deposit and other securities current

No definition available.

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