Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Average Annual Operating Profit Earned Period Maximum	3 years
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value of Financial Instruments The carrying amounts of Brown & Brown’s financial assets and liabilities, including cash and cash equivalents; restricted cash and short-term investments; investments; premiums, commissions and fees receivable; reinsurance recoverable; prepaid reinsurance premiums; premiums payable to insurance companies; losses and loss adjustment reserve; unearned premium; premium deposits and credits due customers and accounts payable, at December 31, 2017 and 2016, approximate fair value because of the short-term maturity of these instruments. The carrying amount of Brown & Brown’s long-term debt approximates fair value at December 31, 2017 and 2016 as our fixed-rate borrowings of $598.9 million approximate their values using market quotes of notes with the similar terms as ours, which we deem a close approximation of current market rates. Of the $598.9 million, $100.0 million is related to short-term notes which approximates the carrying value due to the proximity to maturity. The estimated fair value of the $385.0 million remaining on the term loan under our Amended and Restated Credit Facility (as defined below) approximates the carrying value due to the variable interest rate based upon adjusted LIBOR. See Note 2 to our Consolidated Financial Statements for the fair values related to the establishment of intangible assets and the establishment and adjustment of earn-out payables. See Note 5 for information on the fair value of investments and Note 8 for information on the fair value of long-term debt.
Nature of Operations	Summary of Significant Accounting Policies Nature of Operations Brown & Brown, Inc., a Florida corporation, and its subsidiaries (collectively, “Brown & Brown” or the “Company”) is a diversified insurance agency, wholesale brokerage, insurance programs and services organization that markets and sells to its customers, insurance products and services, primarily in the property, casualty and employee benefits areas. Brown & Brown’s business is divided into four reportable segments: the Retail Segment provides a broad range of insurance products and services to commercial, public and quasi-public entities, professional and individual customers; the National Programs Segment, acting as a managing general agent (“MGA”), provides professional liability and related package products for certain professionals, a range of insurance products for individuals, flood coverage, and targeted products and services designated for specific industries, trade groups, governmental entities and market niches, all of which are delivered through nationwide networks of independent agents, including Brown & Brown retail agents; the Wholesale Brokerage Segment markets and sells excess and surplus commercial insurance, primarily through independent agents and brokers, as well as Brown & Brown Retail offices; and the Services Segment provides insurance-related services, including third-party claims administration and comprehensive medical utilization management services in both the workers’ compensation and all-lines liability arenas, as well as Medicare Set-aside services, Social Security disability and Medicare benefits advocacy services, and claims adjusting services. Recently Issued Accounting Pronouncements In November 2016, the Financial Accountings Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-18, “Statement of Cash Flows (Topic 230)”: Restricted Cash (“ASU 2016-18”), which requires that the Statement of Cash Flows explain the changes during the period of cash and cash equivalents inclusive of amounts categorized as restricted cash. ASU 2016-18 is effective for periods beginning after December 15, 2017. However, the Company elected to early adopt for the reporting period beginning January 1, 2017 under the full retrospective approach for all periods presented. With the adoption of ASU 2016-18, the change in restricted cash is no longer reflected as a change in operating assets and liabilities, and the Statement of Cash Flows details the changes in the balance of cash and cash equivalents inclusive of restricted cash. Net cash provided by operating activities for the years ended December 31, 2015 and 2016 were previously reported as $411.8 million and $375.2 million, respectively. With the retrospective adoption, the net cash provided by operating activities for the years ended December 31, 2015 and 2016 is now reported as $381.8 million and $411.0 million, respectively. The Company reflects cash collected from customers that is payable to insurance companies as restricted cash if segregation of this cash is required by the state of domicile for the office conducting this transaction or if required by contract with the relevant insurance company providing coverage. Cash collected from customers that is payable to insurance companies is reported in cash and cash equivalents if no such restriction is required. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230)”: Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) (“ASU 2016-15”), which addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice in how certain cash receipts and cash payments are presented and classified and applies to all entities, including both business entities and not-for-profit entities that are required to present a statement of cash flows under Topic 230. ASU 2016-15 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017 and early adoption is permitted. The Company is adopting this change effective January 1, 2018 and has evaluated the impact of ASU 2016-15 determining that there is no impact on the Company’s Statement of Cash Flows. The Company already presents cash paid on contingent consideration in business combination as prescribed by ASU 2016-15 and does not, at this time, engage in the other activities being addressed. In March 2016, the FASB issued ASU 2016-09, “Improvements to Employee Share Based Payment Accounting” (“ASU 2016-09”), which amends guidance issued in Accounting Standards Codification (“ASC”) Topic 718, Compensation - Stock Compensation. ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years and early adoption is permitted. The Company adopted the guidance on January 1, 2017, as required. Prior periods have not been adjusted, as the guidance was adopted prospectively. The principal impact is that the tax benefit or expense from stock compensation is now presented in the income tax line of the Statement of Income, whereas the prior treatment was to present this amount as a component of equity on the Balance Sheet. In addition, the tax benefit or expense is now presented as activity in Cash Flow from Operating Activity, rather than the prior presentation as Cash Flow from Financing Activity in the Statement of Cash Flows. The Company also continues to estimate forfeitures of stock grants as allowed by ASU 2016-09. In March 2016, the FASB issued ASU 2016-08, “Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” (“ASU 2016-08”) to clarify certain aspects of the principal-versus-agent guidance included in the new revenue standard ASU 2014-09 “Revenue from Contracts with Customers” (“ASU 2014-09”). The FASB issued the ASU in response to concerns identified by stakeholders, including those related to (1) determining the appropriate unit of account under the revenue standard’s principal-versus-agent guidance and (2) applying the indicators of whether an entity is a principal or an agent in accordance with the revenue standard’s control principle. ASU 2016-08 is effective contemporaneous with ASU 2014-09 beginning January 1, 2018. The impact of adopting ASU 2016-08 is not material to the Company. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” (“ASU 2016-02”), which provides guidance for accounting for leases. Under ASU 2016-02, the Company will be required to recognize the assets and liabilities for the rights and obligations created by leased assets. ASU 2016-02 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company continues to evaluate the impact of this pronouncement with the principal impact being that the present value of the remaining lease payments be presented as a liability on the Balance Sheet as well as an asset of similar value representing the “Right of Use” for those leased properties. As detailed in Note 13 of the 2016 10-K, the undiscounted contractual cash payments remaining on leased properties was $213.2 million as of December 31, 2016 and is $210.4 million as of December 31, 2017 as detailed in “Management’s Discussion and Analysis of Financial Condition and Results of Operations - Liquidity and Capital Resources” and Note 13 “Commitments and Contingencies.” In November 2015, FASB issued ASU No. 2015-17, “Income Taxes (Topic 740) - Balance Sheet Classification of Deferred Taxes” (“ASU 2015-17”), which simplifies the presentation of deferred income taxes by requiring deferred tax assets and liabilities be classified as a single non-current item on the balance sheet. ASU 2015-17 is effective for fiscal years beginning after December 15, 2016 with early adoption permitted as of the beginning of any interim or annual reporting period. The Company adopted the guidance on January 1, 2017, as required. As a result, the Company retrospectively applied the guidance to the 2016 balance sheet by reclassifying $24.6 million from deferred income taxes (asset) to deferred income taxes, net (liability) on the Condensed Consolidated Balance Sheet. This reclassification occurred prior to the passage of the Tax Cuts and Jobs Act of 2017, which had a material impact on the value of deferred tax items. See Note 9 “Income Taxes” for more information. In May 2014, FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” (“Topic 606”), which provides guidance for revenue recognition. Topic 606 affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets. It supersedes the revenue recognition requirements in Topic 605, “Revenue Recognition,” and most industry-specific guidance. The standard’s core principle is that a company should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which a company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under the current guidance. Specifically, in situations where multiple performance obligations exist within a contract, the use of estimates is required to allocate the transaction price to each separate performance obligation. Historically, approximately 70% of the Company’s commissions and fees are in the form of commissions paid by insurance carriers. These commissions are earned upon the effective date of bound coverage, as no significant performance obligation remains after coverage is bound. The following areas are impacted by the adoption of Topic 606: Installment billing - Prior to the adoption of Topic 606, commission revenues related to installment billings were recognized on the latter of the policy effective date (as indicated in the policy) or the date that the premium was billed to the client (as indicated on the premium invoice), with the exception of our Arrowhead businesses, which follow a policy of recognizing these revenues on the latter of the policy effective date or processed date into our systems, regardless of the billing arrangement. As a result of the adoption of Topic 606, revenue associated with the issuance of policies will be recognized upon the effective date of the associated policy, which means that commission revenues billed on an installment basis will be now recognized earlier than they had been previously resulting in revenue will accrued based upon the completion of the performance obligation and thus creating a current asset for the unbilled revenue until such time as an invoice is generated, typically not to exceed twelve months. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years. Contingent commissions - Prior to the adoption of Topic 606, revenue that was not fixed and determinable because a contingency exists was not recognized until the contingency was resolved. Under Topic 606, the Company must use its judgment to estimate the amount of consideration that will be received such that a significant reversal of revenue is not probable. Contingent commissions represent a form of variable consideration associated with the same performance obligation, which is the placement of coverage, for which we earn core commissions. In connection with the new standard, contingent commissions will be estimated with an appropriate constraint applied and accrued relative to the recognition of the corresponding core commissions. The resulting effect on the timing of recognition of contingent commissions will more closely follow a similar pattern as our core commissions with true-ups recognized when payments are received or as additional information that affects the estimate becomes available. Contingent commissions have averaged approximately 3.6% of the previous year’s total commissions and fees over the last three years and have primarily been received in the first and second quarters of the year. Approximately 30% of the Company’s commissions and fees is in the form of fees, which are predominantly in our National Programs and Services Segments, and to a lesser extent in the large accounts business within our Retail Segment, where we receive fees in lieu of a commission. In accordance with Topic 606, fee revenue from certain agreements will be recognized in earlier periods and others in later periods as compared to our current accounting treatment. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years. Additionally, the Company has evaluated ASC Topic 340 - Other Assets and Deferred Cost (“ASC 340”) which requires companies to defer certain incremental costs to obtain customer contracts, and certain costs to fulfill customer contracts. Incremental cost to obtain - the adoption of ASC 340 will result in the Company deferring certain cost to obtain customer contracts primarily as they relate to commission based compensation plans in the Retail Segment, in which the Company pays an incremental amount of compensation on new business in the first year of the contract. These incremental costs will be deferred and amortized over a 15-year period, which is consistent with the analysis performed on acquired customer accounts and referenced in Note 4 to the Company’s financial statements. Cost to fulfill - the adoption of ASC 340 will result in the Company deferring certain costs to fulfill a contract and recognize these costs as the associated performance obligations are fulfilled. In order for contract fulfillment costs to be deferred under ASC 340, the costs must (1) relate directly to a specific contract or anticipated contract, (2) generate or enhance resources that the Company will use in satisfying its obligations under the contract, and (3) be expected to be recovered through sufficient net cash flows from the contract. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing these expenses will be impacted among quarters to better align with the associated revenue. Topic 606 is effective for the Company beginning January 1, 2018. Entities are permitted to adopt the guidance under one of the following methods: the “full retrospective” method, which applies the guidance to each period presented (prior years restated), or the “modified retrospective” method, in which the guidance is only applied to the year of adoption, with the cumulative effect of initially applying the guidance recognized as an adjustment to retained earnings. The Company has elected to follow the modified retrospective method applied to contracts that are not completed as of the date of adoption. The estimated cumulative impact of adopting the standard on January 1, 2018 is an increase in stockholders’ equity of between $70.0 million and $110.0 million. In connection with the implementation of this standard, we expect to modify, and in some instances institute additional accounting procedures, processes and internal controls. Given the relative expected impacts of this standard to our revenue streams, we do not expect that these modifications and additions will materially change our internal controls over financial reporting. Principles of Consolidation The accompanying Consolidated Financial Statements include the accounts of Brown & Brown, Inc. and its subsidiaries. All significant intercompany account balances and transactions have been eliminated in the Consolidated Financial Statements. Segment results for prior periods have been recast, where appropriate, to reflect the current year segmental structure. Certain reclassifications have been made to the prior year amounts reported in this Annual Report on Form 10-K in order to conform to the current year presentation. Revenue Recognition Commission revenues are recognized as of the effective date of the insurance policy or the date on which the policy premium is processed into our systems and invoiced to the customer, whichever is later. Commission revenues related to installment billings are recognized on the latter of effective or invoiced date, with the exception of our Arrowhead business which follows a policy of recognizing on the latter of effective or processed date into our systems, regardless of the billing arrangement. Management determines the policy cancellation reserve based upon historical cancellation experience adjusted for any known circumstances. Subsequent commission adjustments were recognized upon our receipt of notification from insurance companies concerning matters necessitating such adjustments. Profit-sharing contingent commissions are recognized when determinable, which is generally when such commissions are received from insurance companies, or when we receive formal notification of the amount of such payments. Fee revenues and commissions for workers’ compensation programs are recognized as services are rendered. Use of Estimates The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, as well as disclosures of contingent assets and liabilities, at the date of the Consolidated Financial Statements, and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from those estimates. Cash and Cash Equivalents Cash and cash equivalents principally consist of demand deposits with financial institutions and highly liquid investments with quoted market prices having maturities of three months or less when purchased. Restricted Cash and Investments, and Premiums, Commissions and Fees Receivable In our capacity as an insurance agent or broker, the Company typically collects premiums from insureds and, after deducting the authorized commissions, remits the net premiums to the appropriate insurance company or companies. Accordingly, as reported in the Consolidated Balance Sheets, “premiums” are receivable from insureds. Unremitted net insurance premiums are held in a fiduciary capacity until Brown & Brown disburses them. Where allowed by law, Brown & Brown invests these unremitted funds only in cash, money market accounts, tax-free variable-rate demand bonds and commercial paper held for a short term. In certain states in which Brown & Brown operates, the use and investment alternatives for these funds are regulated and restricted by various state laws and agencies. These restricted funds are reported as restricted cash and investments on the Consolidated Balance Sheets. The interest income earned on these unremitted funds, where allowed by state law, is reported as investment income in the Consolidated Statement of Income. In other circumstances, the insurance companies collect the premiums directly from the insureds and remit the applicable commissions to Brown & Brown. Accordingly, as reported in the Consolidated Balance Sheets, “commissions” are receivables from insurance companies. “Fees” are primarily receivables due from customers. Investments Certificates of deposit, and other securities, having maturities of more than three months when purchased are reported at cost and are adjusted for other-than-temporary market value declines. The Company’s investment holdings include U.S. Government securities, municipal bonds, domestic corporate and foreign corporate bonds as well as short-duration fixed income funds. Investments within the portfolio or funds are held as available for sale and are carried at their fair value. Any gain/loss applicable from the fair value change is recorded, net of tax, as other comprehensive income within the equity section of the Consolidated Balance Sheet. Realized gains and losses are reported on the Consolidated Statement of Income, with the cost of securities sold determined on a specific identification basis. Fixed Assets Fixed assets, including leasehold improvements, are carried at cost, less accumulated depreciation and amortization. Expenditures for improvements are capitalized, and expenditures for maintenance and repairs are expensed to operations as incurred. Upon sale or retirement, the cost and related accumulated depreciation and amortization are removed from the accounts and the resulting gain or loss, if any, is reflected in other income. Depreciation has been determined using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 15 years. Leasehold improvements are amortized on the straight-line method over the shorter of the useful life of the improvement or the term of the related lease. Goodwill and Amortizable Intangible Assets All of our business combinations initiated after June 30, 2001 are accounted for using the acquisition method. Acquisition purchase prices are typically based upon a multiple of average annual operating profit earned over a period of 3 years within a minimum and maximum price range. The recorded purchase prices for all acquisitions consummated after January 1, 2009 include an estimation of the fair value of liabilities associated with any potential earn-out provisions. Subsequent changes in the fair value of earn-out obligations are recorded in the Consolidated Statement of Income when incurred. The fair value of earn-out obligations is based upon the present value of the expected future payments to be made to the sellers of the acquired businesses in accordance with the provisions contained in the respective purchase agreements. In determining fair value, the acquired business’ future performance is estimated using financial projections developed by management for the acquired business and this estimate reflects market participant assumptions regarding revenue growth and/or profitability. The expected future payments are estimated on the basis of the earn-out formula and performance targets specified in each purchase agreement compared to the associated financial projections. These estimates are then discounted to present value using a risk-adjusted rate that takes into consideration the likelihood that the forecasted earn-out payments will be made. Amortizable intangible assets are stated at cost, less accumulated amortization, and consist of purchased customer accounts and non-compete agreements. Purchased customer accounts and non-compete agreements are amortized on a straight-line basis over the related estimated lives and contract periods, which range from 3 to 15 years. Purchased customer accounts primarily consist of records and files that contain information about insurance policies and the related insured parties that are essential to policy renewals. The excess of the purchase price of an acquisition over the fair value of the identifiable tangible and amortizable intangible assets is assigned to goodwill. While goodwill is not amortizable, it is subject to assessment at least annually, and more frequently in the presence of certain circumstances, for impairment by application of a fair value-based test. The Company compares the fair value of each reporting unit with its carrying amount to determine if there is potential impairment of goodwill. If the fair value of the reporting unit is less than its carrying value, an impairment loss is recorded to the extent that the fair value of the goodwill within the reporting unit is less than its carrying value. Fair value is estimated based upon multiples of earnings before interest, income taxes, depreciation, amortization and change in estimated acquisition earn-out payables (“EBITDAC”), or on a discounted cash flow basis. Brown & Brown completed its most recent annual assessment as of November 30, 2017 and determined that the fair value of goodwill significantly exceeded the carrying value of such assets. In addition, as of December 31, 2017, there are no accumulated impairment losses. The carrying value of amortizable intangible assets attributable to each business or asset group comprising Brown & Brown is periodically reviewed by management to determine if there are events or changes in circumstances that would indicate that its carrying amount may not be recoverable. Accordingly, if there are any such changes in circumstances during the year, Brown & Brown assesses the carrying value of its amortizable intangible assets by considering the estimated future undiscounted cash flows generated by the corresponding business or asset group. Any impairment identified through this assessment may require that the carrying value of related amortizable intangible assets be adjusted. There were no impairments recorded for the years ended December 31, 2017, 2016 and 2015. Income Taxes Brown & Brown records income tax expense using the asset-and-liability method of accounting for deferred income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement carrying values and the income tax bases of Brown & Brown’s assets and liabilities. Brown & Brown files a consolidated federal income tax return and has elected to file consolidated returns in certain states. Deferred income taxes are provided for in the Consolidated Financial Statements and relate principally to expenses charged to income for financial reporting purposes in one period and deducted for income tax purposes in other periods.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In November 2016, the Financial Accountings Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-18, “Statement of Cash Flows (Topic 230)”: Restricted Cash (“ASU 2016-18”), which requires that the Statement of Cash Flows explain the changes during the period of cash and cash equivalents inclusive of amounts categorized as restricted cash. ASU 2016-18 is effective for periods beginning after December 15, 2017. However, the Company elected to early adopt for the reporting period beginning January 1, 2017 under the full retrospective approach for all periods presented. With the adoption of ASU 2016-18, the change in restricted cash is no longer reflected as a change in operating assets and liabilities, and the Statement of Cash Flows details the changes in the balance of cash and cash equivalents inclusive of restricted cash. Net cash provided by operating activities for the years ended December 31, 2015 and 2016 were previously reported as $411.8 million and $375.2 million, respectively. With the retrospective adoption, the net cash provided by operating activities for the years ended December 31, 2015 and 2016 is now reported as $381.8 million and $411.0 million, respectively. The Company reflects cash collected from customers that is payable to insurance companies as restricted cash if segregation of this cash is required by the state of domicile for the office conducting this transaction or if required by contract with the relevant insurance company providing coverage. Cash collected from customers that is payable to insurance companies is reported in cash and cash equivalents if no such restriction is required. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230)”: Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) (“ASU 2016-15”), which addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice in how certain cash receipts and cash payments are presented and classified and applies to all entities, including both business entities and not-for-profit entities that are required to present a statement of cash flows under Topic 230. ASU 2016-15 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017 and early adoption is permitted. The Company is adopting this change effective January 1, 2018 and has evaluated the impact of ASU 2016-15 determining that there is no impact on the Company’s Statement of Cash Flows. The Company already presents cash paid on contingent consideration in business combination as prescribed by ASU 2016-15 and does not, at this time, engage in the other activities being addressed. In March 2016, the FASB issued ASU 2016-09, “Improvements to Employee Share Based Payment Accounting” (“ASU 2016-09”), which amends guidance issued in Accounting Standards Codification (“ASC”) Topic 718, Compensation - Stock Compensation. ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years and early adoption is permitted. The Company adopted the guidance on January 1, 2017, as required. Prior periods have not been adjusted, as the guidance was adopted prospectively. The principal impact is that the tax benefit or expense from stock compensation is now presented in the income tax line of the Statement of Income, whereas the prior treatment was to present this amount as a component of equity on the Balance Sheet. In addition, the tax benefit or expense is now presented as activity in Cash Flow from Operating Activity, rather than the prior presentation as Cash Flow from Financing Activity in the Statement of Cash Flows. The Company also continues to estimate forfeitures of stock grants as allowed by ASU 2016-09. In March 2016, the FASB issued ASU 2016-08, “Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” (“ASU 2016-08”) to clarify certain aspects of the principal-versus-agent guidance included in the new revenue standard ASU 2014-09 “Revenue from Contracts with Customers” (“ASU 2014-09”). The FASB issued the ASU in response to concerns identified by stakeholders, including those related to (1) determining the appropriate unit of account under the revenue standard’s principal-versus-agent guidance and (2) applying the indicators of whether an entity is a principal or an agent in accordance with the revenue standard’s control principle. ASU 2016-08 is effective contemporaneous with ASU 2014-09 beginning January 1, 2018. The impact of adopting ASU 2016-08 is not material to the Company. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” (“ASU 2016-02”), which provides guidance for accounting for leases. Under ASU 2016-02, the Company will be required to recognize the assets and liabilities for the rights and obligations created by leased assets. ASU 2016-02 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company continues to evaluate the impact of this pronouncement with the principal impact being that the present value of the remaining lease payments be presented as a liability on the Balance Sheet as well as an asset of similar value representing the “Right of Use” for those leased properties. As detailed in Note 13 of the 2016 10-K, the undiscounted contractual cash payments remaining on leased properties was $213.2 million as of December 31, 2016 and is $210.4 million as of December 31, 2017 as detailed in “Management’s Discussion and Analysis of Financial Condition and Results of Operations - Liquidity and Capital Resources” and Note 13 “Commitments and Contingencies.” In November 2015, FASB issued ASU No. 2015-17, “Income Taxes (Topic 740) - Balance Sheet Classification of Deferred Taxes” (“ASU 2015-17”), which simplifies the presentation of deferred income taxes by requiring deferred tax assets and liabilities be classified as a single non-current item on the balance sheet. ASU 2015-17 is effective for fiscal years beginning after December 15, 2016 with early adoption permitted as of the beginning of any interim or annual reporting period. The Company adopted the guidance on January 1, 2017, as required. As a result, the Company retrospectively applied the guidance to the 2016 balance sheet by reclassifying $24.6 million from deferred income taxes (asset) to deferred income taxes, net (liability) on the Condensed Consolidated Balance Sheet. This reclassification occurred prior to the passage of the Tax Cuts and Jobs Act of 2017, which had a material impact on the value of deferred tax items. See Note 9 “Income Taxes” for more information. In May 2014, FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” (“Topic 606”), which provides guidance for revenue recognition. Topic 606 affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets. It supersedes the revenue recognition requirements in Topic 605, “Revenue Recognition,” and most industry-specific guidance. The standard’s core principle is that a company should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which a company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under the current guidance. Specifically, in situations where multiple performance obligations exist within a contract, the use of estimates is required to allocate the transaction price to each separate performance obligation. Historically, approximately 70% of the Company’s commissions and fees are in the form of commissions paid by insurance carriers. These commissions are earned upon the effective date of bound coverage, as no significant performance obligation remains after coverage is bound. The following areas are impacted by the adoption of Topic 606: Installment billing - Prior to the adoption of Topic 606, commission revenues related to installment billings were recognized on the latter of the policy effective date (as indicated in the policy) or the date that the premium was billed to the client (as indicated on the premium invoice), with the exception of our Arrowhead businesses, which follow a policy of recognizing these revenues on the latter of the policy effective date or processed date into our systems, regardless of the billing arrangement. As a result of the adoption of Topic 606, revenue associated with the issuance of policies will be recognized upon the effective date of the associated policy, which means that commission revenues billed on an installment basis will be now recognized earlier than they had been previously resulting in revenue will accrued based upon the completion of the performance obligation and thus creating a current asset for the unbilled revenue until such time as an invoice is generated, typically not to exceed twelve months. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years. Contingent commissions - Prior to the adoption of Topic 606, revenue that was not fixed and determinable because a contingency exists was not recognized until the contingency was resolved. Under Topic 606, the Company must use its judgment to estimate the amount of consideration that will be received such that a significant reversal of revenue is not probable. Contingent commissions represent a form of variable consideration associated with the same performance obligation, which is the placement of coverage, for which we earn core commissions. In connection with the new standard, contingent commissions will be estimated with an appropriate constraint applied and accrued relative to the recognition of the corresponding core commissions. The resulting effect on the timing of recognition of contingent commissions will more closely follow a similar pattern as our core commissions with true-ups recognized when payments are received or as additional information that affects the estimate becomes available. Contingent commissions have averaged approximately 3.6% of the previous year’s total commissions and fees over the last three years and have primarily been received in the first and second quarters of the year. Approximately 30% of the Company’s commissions and fees is in the form of fees, which are predominantly in our National Programs and Services Segments, and to a lesser extent in the large accounts business within our Retail Segment, where we receive fees in lieu of a commission. In accordance with Topic 606, fee revenue from certain agreements will be recognized in earlier periods and others in later periods as compared to our current accounting treatment. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years. Additionally, the Company has evaluated ASC Topic 340 - Other Assets and Deferred Cost (“ASC 340”) which requires companies to defer certain incremental costs to obtain customer contracts, and certain costs to fulfill customer contracts. Incremental cost to obtain - the adoption of ASC 340 will result in the Company deferring certain cost to obtain customer contracts primarily as they relate to commission based compensation plans in the Retail Segment, in which the Company pays an incremental amount of compensation on new business in the first year of the contract. These incremental costs will be deferred and amortized over a 15-year period, which is consistent with the analysis performed on acquired customer accounts and referenced in Note 4 to the Company’s financial statements. Cost to fulfill - the adoption of ASC 340 will result in the Company deferring certain costs to fulfill a contract and recognize these costs as the associated performance obligations are fulfilled. In order for contract fulfillment costs to be deferred under ASC 340, the costs must (1) relate directly to a specific contract or anticipated contract, (2) generate or enhance resources that the Company will use in satisfying its obligations under the contract, and (3) be expected to be recovered through sufficient net cash flows from the contract. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing these expenses will be impacted among quarters to better align with the associated revenue. Topic 606 is effective for the Company beginning January 1, 2018. Entities are permitted to adopt the guidance under one of the following methods: the “full retrospective” method, which applies the guidance to each period presented (prior years restated), or the “modified retrospective” method, in which the guidance is only applied to the year of adoption, with the cumulative effect of initially applying the guidance recognized as an adjustment to retained earnings. The Company has elected to follow the modified retrospective method applied to contracts that are not completed as of the date of adoption. The estimated cumulative impact of adopting the standard on January 1, 2018 is an increase in stockholders’ equity of between $70.0 million and $110.0 million. In connection with the implementation of this standard, we expect to modify, and in some instances institute additional accounting procedures, processes and internal controls. Given the relative expected impacts of this standard to our revenue streams, we do not expect that these modifications and additions will materially change our internal controls over financial reporting.
Consolidation, Policy [Policy Text Block]	Principles of Consolidation The accompanying Consolidated Financial Statements include the accounts of Brown & Brown, Inc. and its subsidiaries. All significant intercompany account balances and transactions have been eliminated in the Consolidated Financial Statements. Segment results for prior periods have been recast, where appropriate, to reflect the current year segmental structure. Certain reclassifications have been made to the prior year amounts reported in this Annual Report on Form 10-K in order to conform to the current year presentation.
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition Commission revenues are recognized as of the effective date of the insurance policy or the date on which the policy premium is processed into our systems and invoiced to the customer, whichever is later. Commission revenues related to installment billings are recognized on the latter of effective or invoiced date, with the exception of our Arrowhead business which follows a policy of recognizing on the latter of effective or processed date into our systems, regardless of the billing arrangement. Management determines the policy cancellation reserve based upon historical cancellation experience adjusted for any known circumstances. Subsequent commission adjustments were recognized upon our receipt of notification from insurance companies concerning matters necessitating such adjustments. Profit-sharing contingent commissions are recognized when determinable, which is generally when such commissions are received from insurance companies, or when we receive formal notification of the amount of such payments. Fee revenues and commissions for workers’ compensation programs are recognized as services are rendered.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, as well as disclosures of contingent assets and liabilities, at the date of the Consolidated Financial Statements, and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from those estimates
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents Cash and cash equivalents principally consist of demand deposits with financial institutions and highly liquid investments with quoted market prices having maturities of three months or less when purchased.
Restricted Cash and Investments Premiums Commissions and Fees Receivable Policy [Text Block]	Restricted Cash and Investments, and Premiums, Commissions and Fees Receivable In our capacity as an insurance agent or broker, the Company typically collects premiums from insureds and, after deducting the authorized commissions, remits the net premiums to the appropriate insurance company or companies. Accordingly, as reported in the Consolidated Balance Sheets, “premiums” are receivable from insureds. Unremitted net insurance premiums are held in a fiduciary capacity until Brown & Brown disburses them. Where allowed by law, Brown & Brown invests these unremitted funds only in cash, money market accounts, tax-free variable-rate demand bonds and commercial paper held for a short term. In certain states in which Brown & Brown operates, the use and investment alternatives for these funds are regulated and restricted by various state laws and agencies. These restricted funds are reported as restricted cash and investments on the Consolidated Balance Sheets. The interest income earned on these unremitted funds, where allowed by state law, is reported as investment income in the Consolidated Statement of Income. In other circumstances, the insurance companies collect the premiums directly from the insureds and remit the applicable commissions to Brown & Brown. Accordingly, as reported in the Consolidated Balance Sheets, “commissions” are receivables from insurance companies. “Fees” are primarily receivables due from customers.
Investment, Policy [Policy Text Block]	Investments Certificates of deposit, and other securities, having maturities of more than three months when purchased are reported at cost and are adjusted for other-than-temporary market value declines. The Company’s investment holdings include U.S. Government securities, municipal bonds, domestic corporate and foreign corporate bonds as well as short-duration fixed income funds. Investments within the portfolio or funds are held as available for sale and are carried at their fair value. Any gain/loss applicable from the fair value change is recorded, net of tax, as other comprehensive income within the equity section of the Consolidated Balance Sheet. Realized gains and losses are reported on the Consolidated Statement of Income, with the cost of securities sold determined on a specific identification basis
Property, Plant and Equipment, Policy [Policy Text Block]	Fixed Assets Fixed assets, including leasehold improvements, are carried at cost, less accumulated depreciation and amortization. Expenditures for improvements are capitalized, and expenditures for maintenance and repairs are expensed to operations as incurred. Upon sale or retirement, the cost and related accumulated depreciation and amortization are removed from the accounts and the resulting gain or loss, if any, is reflected in other income. Depreciation has been determined using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 15 years. Leasehold improvements are amortized on the straight-line method over the shorter of the useful life of the improvement or the term of the related lease.
Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block]	Goodwill and Amortizable Intangible Assets All of our business combinations initiated after June 30, 2001 are accounted for using the acquisition method. Acquisition purchase prices are typically based upon a multiple of average annual operating profit earned over a period of 3 years within a minimum and maximum price range. The recorded purchase prices for all acquisitions consummated after January 1, 2009 include an estimation of the fair value of liabilities associated with any potential earn-out provisions. Subsequent changes in the fair value of earn-out obligations are recorded in the Consolidated Statement of Income when incurred. The fair value of earn-out obligations is based upon the present value of the expected future payments to be made to the sellers of the acquired businesses in accordance with the provisions contained in the respective purchase agreements. In determining fair value, the acquired business’ future performance is estimated using financial projections developed by management for the acquired business and this estimate reflects market participant assumptions regarding revenue growth and/or profitability. The expected future payments are estimated on the basis of the earn-out formula and performance targets specified in each purchase agreement compared to the associated financial projections. These estimates are then discounted to present value using a risk-adjusted rate that takes into consideration the likelihood that the forecasted earn-out payments will be made. Amortizable intangible assets are stated at cost, less accumulated amortization, and consist of purchased customer accounts and non-compete agreements. Purchased customer accounts and non-compete agreements are amortized on a straight-line basis over the related estimated lives and contract periods, which range from 3 to 15 years. Purchased customer accounts primarily consist of records and files that contain information about insurance policies and the related insured parties that are essential to policy renewals. The excess of the purchase price of an acquisition over the fair value of the identifiable tangible and amortizable intangible assets is assigned to goodwill. While goodwill is not amortizable, it is subject to assessment at least annually, and more frequently in the presence of certain circumstances, for impairment by application of a fair value-based test. The Company compares the fair value of each reporting unit with its carrying amount to determine if there is potential impairment of goodwill. If the fair value of the reporting unit is less than its carrying value, an impairment loss is recorded to the extent that the fair value of the goodwill within the reporting unit is less than its carrying value. Fair value is estimated based upon multiples of earnings before interest, income taxes, depreciation, amortization and change in estimated acquisition earn-out payables (“EBITDAC”), or on a discounted cash flow basis. Brown & Brown completed its most recent annual assessment as of November 30, 2017 and determined that the fair value of goodwill significantly exceeded the carrying value of such assets. In addition, as of December 31, 2017, there are no accumulated impairment losses. The carrying value of amortizable intangible assets attributable to each business or asset group comprising Brown & Brown is periodically reviewed by management to determine if there are events or changes in circumstances that would indicate that its carrying amount may not be recoverable. Accordingly, if there are any such changes in circumstances during the year, Brown & Brown assesses the carrying value of its amortizable intangible assets by considering the estimated future undiscounted cash flows generated by the corresponding business or asset group. Any impairment identified through this assessment may require that the carrying value of related amortizable intangible assets be adjusted. There were no impairments recorded for the years ended December 31, 2017, 2016 and 2015.
Income Tax, Policy [Policy Text Block]	Income Taxes Brown & Brown records income tax expense using the asset-and-liability method of accounting for deferred income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement carrying values and the income tax bases of Brown & Brown’s assets and liabilities. Brown & Brown files a consolidated federal income tax return and has elected to file consolidated returns in certain states. Deferred income taxes are provided for in the Consolidated Financial Statements and relate principally to expenses charged to income for financial reporting purposes in one period and deducted for income tax purposes in other periods.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Stock-Based Compensation The Company has granted stock options and grants non-vested stock awards to its employees and officers and fully vested stock awards to directors. The Company uses the modified-prospective method to account for share-based payments. Under the modified-prospective method, compensation cost is recognized for all share-based payments granted on or after January 1, 2006 and for all awards granted to employees prior to January 1, 2006 that remained unvested on that date. The Company uses the alternative-transition method to account for the income tax effects of payments made related to stock-based compensation. The Company uses the Black-Scholes valuation model for valuing all stock options and shares purchased under the Employee Stock Purchase Plan (the “ESPP”). Compensation for non-vested stock awards is measured at fair value on the grant date based upon the number of shares expected to vest. Compensation cost for all awards is recognized in earnings, net of estimated forfeitures, on a straight-line basis over the requisite service period
Reinsurance Accounting Policy [Policy Text Block]	Reinsurance The Company protects itself from claims-related losses by reinsuring all claims risk exposure. The only line of insurance the Company underwrites is flood insurance associated with the Wright National Flood Insurance Company (“WNFIC”), which is part of our National Programs Segment. However, all exposure is reinsured with the Federal Emergency Management Agency (“FEMA”) for basic admitted policies conforming to the National Flood Insurance Program. For excess flood insurance policies, all exposure is reinsured with a reinsurance carrier with an AM Best Company rating of “A” or better. Reinsurance does not legally discharge the ceding insurer from the primary liability for the full amount due under the reinsured policies. Reinsurance premiums, commissions, expense reimbursement and reserves related to ceded business are accounted for on a basis consistent with the accounting for the original policies issued and the terms of reinsurance contracts. Premiums earned and losses and loss adjustment expenses incurred are reported net of reinsurance amounts. Other underwriting expenses are shown net of earned ceding commission income. The liabilities for unpaid losses and loss adjustment expenses and unearned premiums are reported gross of ceded reinsurance recoverable. Balances due from reinsurers on unpaid losses and loss adjustment expenses, including an estimate of such recoverables related to reserves for incurred but not reported (“IBNR”) losses, are reported as assets and are included in reinsurance recoverable even though amounts due on unpaid loss and loss adjustment expense are not recoverable from the reinsurer until such losses are paid. The Company does not believe it is exposed to any material credit risk through its reinsurance as the reinsurer is FEMA for basic admitted flood policies and a national reinsurance carrier for excess flood policies, which has an AM Best Company rating of “A” or better. Historically, no amounts due from reinsurance carriers have been written off as uncollectible.
Unpaid Policy Claims and Claims Adjustment Expense, Policy [Policy Text Block]	Unpaid Losses and Loss Adjustment Reserve Unpaid losses and loss adjustment reserve include amounts determined on individual claims and other estimates based upon the past experience of WNFIC and the policyholders for IBNR claims, less anticipated salvage and subrogation recoverable. The methods of making such estimates and for establishing the resulting reserves are continually reviewed and updated, and any adjustments resulting therefrom are reflected in operations currently. WNFIC engages the services of outside actuarial consulting firms (the “Actuaries”) to assist on an annual basis to render an opinion on the sufficiency of the Company’s estimates for unpaid losses and related loss adjustment reserve. The Actuaries utilize both industry experience and the Company’s own experience to develop estimates of those amounts as of year-end. These estimated liabilities are subject to the impact of future changes in claim severity, frequency and other factors. In spite of the variability inherent in such estimates, management believes that the liabilities for unpaid losses and related loss adjustment reserve are adequate.
Insurance Premiums Revenue Recognition, Policy [Policy Text Block]	PremiumsPremiums are recognized as income over the coverage period of the related policies. Unearned premiums represent the portion of premiums written that relate to the unexpired terms of the policies in force and are determined on a daily pro rata basis. The income is recorded to the commissions and fees line of the income statement.
Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	15 years

Average Annual Operating Profit Earned Period Maximum

3 years

Summary of Significant Accounting Policies

Nature of Operations

Brown & Brown, Inc., a Florida corporation, and its subsidiaries (collectively, “Brown & Brown” or the “Company”) is a diversified insurance agency, wholesale brokerage, insurance programs and services organization that markets and sells to its customers, insurance products and services, primarily in the property, casualty and employee benefits areas. Brown & Brown’s business is divided into four reportable segments: the Retail Segment provides a broad range of insurance products and services to commercial, public and quasi-public entities, professional and individual customers; the National Programs Segment, acting as a managing general agent (“MGA”), provides professional liability and related package products for certain professionals, a range of insurance products for individuals, flood coverage, and targeted products and services designated for specific industries, trade groups, governmental entities and market niches, all of which are delivered through nationwide networks of independent agents, including Brown & Brown retail agents; the Wholesale Brokerage Segment markets and sells excess and surplus commercial insurance, primarily through independent agents and brokers, as well as Brown & Brown Retail offices; and the Services Segment provides insurance-related services, including third-party claims administration and comprehensive medical utilization management services in both the workers’ compensation and all-lines liability arenas, as well as Medicare Set-aside services, Social Security disability and Medicare benefits advocacy services, and claims adjusting services.

Recently Issued Accounting Pronouncements

In November 2016, the Financial Accountings Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-18, “Statement of Cash Flows (Topic 230)”: Restricted Cash (“ASU 2016-18”), which requires that the Statement of Cash Flows explain the changes during the period of cash and cash equivalents inclusive of amounts categorized as restricted cash. ASU 2016-18 is effective for periods beginning after December 15, 2017. However, the Company elected to early adopt for the reporting period beginning January 1, 2017 under the full retrospective approach for all periods presented. With the adoption of ASU 2016-18, the change in restricted cash is no longer reflected as a change in operating assets and liabilities, and the Statement of Cash Flows details the changes in the balance of cash and cash equivalents inclusive of restricted cash. Net cash provided by operating activities for the years ended December 31, 2015 and 2016 were previously reported as $411.8 million and $375.2 million, respectively. With the retrospective adoption, the net cash provided by operating activities for the years ended December 31, 2015 and 2016 is now reported as $381.8 million and $411.0 million, respectively. The Company reflects cash collected from customers that is payable to insurance companies as restricted cash if segregation of this cash is required by the state of domicile for the office conducting this transaction or if required by contract with the relevant insurance company providing coverage. Cash collected from customers that is payable to insurance companies is reported in cash and cash equivalents if no such restriction is required.

In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230)”: Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) (“ASU 2016-15”), which addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice in how certain cash receipts and cash payments are presented and classified and applies to all entities, including both business entities and not-for-profit entities that are required to present a statement of cash flows under Topic 230. ASU 2016-15 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017 and early adoption is permitted. The Company is adopting this change effective January 1, 2018 and has evaluated the impact of ASU 2016-15 determining that there is no impact on the Company’s Statement of Cash Flows. The Company already presents cash paid on contingent consideration in business combination as prescribed by ASU 2016-15 and does not, at this time, engage in the other activities being addressed.

In March 2016, the FASB issued ASU 2016-09, “Improvements to Employee Share Based Payment Accounting” (“ASU 2016-09”), which amends guidance issued in Accounting Standards Codification (“ASC”) Topic 718, Compensation - Stock Compensation. ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years and early adoption is permitted. The Company adopted the guidance on January 1, 2017, as required. Prior periods have not been adjusted, as the guidance was adopted prospectively. The principal impact is that the tax benefit or expense from stock compensation is now presented in the income tax line of the Statement of Income, whereas the prior treatment was to present this amount as a component of equity on the Balance Sheet. In addition, the tax benefit or expense is now presented as activity in Cash Flow from Operating Activity, rather than the prior presentation as Cash Flow from Financing Activity in the Statement of Cash Flows. The Company also continues to estimate forfeitures of stock grants as allowed by ASU 2016-09.

In March 2016, the FASB issued ASU 2016-08, “Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” (“ASU 2016-08”) to clarify certain aspects of the principal-versus-agent guidance included in the new revenue standard ASU 2014-09 “Revenue from Contracts with Customers” (“ASU 2014-09”). The FASB issued the ASU in response to concerns identified by stakeholders, including those related to (1) determining the appropriate unit of account under the revenue standard’s principal-versus-agent guidance and (2) applying the indicators of whether an entity is a principal or an agent in accordance with the revenue standard’s control principle. ASU 2016-08 is effective contemporaneous with ASU 2014-09 beginning January 1, 2018. The impact of adopting ASU 2016-08 is not material to the Company.

In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” (“ASU 2016-02”), which provides guidance for accounting for leases. Under ASU 2016-02, the Company will be required to recognize the assets and liabilities for the rights and obligations created by leased assets. ASU 2016-02 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company continues to evaluate the impact of this pronouncement with the principal impact being that the present value of the remaining lease payments be presented as a liability on the Balance Sheet as well as an asset of similar value representing the “Right of Use” for those leased properties. As detailed in Note 13 of the 2016 10-K, the undiscounted contractual cash payments remaining on leased properties was $213.2 million as of December 31, 2016 and is $210.4 million as of December 31, 2017 as detailed in “Management’s Discussion and Analysis of Financial Condition and Results of Operations - Liquidity and Capital Resources” and Note 13 “Commitments and Contingencies.”

In November 2015, FASB issued ASU No. 2015-17, “Income Taxes (Topic 740) - Balance Sheet Classification of Deferred Taxes” (“ASU 2015-17”), which simplifies the presentation of deferred income taxes by requiring deferred tax assets and liabilities be classified as a single non-current item on the balance sheet. ASU 2015-17 is effective for fiscal years beginning after December 15, 2016 with early adoption permitted as of the beginning of any interim or annual reporting period. The Company adopted the guidance on January 1, 2017, as required. As a result, the Company retrospectively applied the guidance to the 2016 balance sheet by reclassifying $24.6 million from deferred income taxes (asset) to deferred income taxes, net (liability) on the Condensed Consolidated Balance Sheet. This reclassification occurred prior to the passage of the Tax Cuts and Jobs Act of 2017, which had a material impact on the value of deferred tax items. See Note 9 “Income Taxes” for more information.

In May 2014, FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” (“Topic 606”), which provides guidance for revenue recognition. Topic 606 affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets. It supersedes the revenue recognition requirements in Topic 605, “Revenue Recognition,” and most industry-specific guidance. The standard’s core principle is that a company should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which a company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under the current guidance. Specifically, in situations where multiple performance obligations exist within a contract, the use of estimates is required to allocate the transaction price to each separate performance obligation.

Historically, approximately 70% of the Company’s commissions and fees are in the form of commissions paid by insurance carriers. These commissions are earned upon the effective date of bound coverage, as no significant performance obligation remains after coverage is bound. The following areas are impacted by the adoption of Topic 606:

Installment billing - Prior to the adoption of Topic 606, commission revenues related to installment billings were recognized on the latter of the policy effective date (as indicated in the policy) or the date that the premium was billed to the client (as indicated on the premium invoice), with the exception of our Arrowhead businesses, which follow a policy of recognizing these revenues on the latter of the policy effective date or processed date into our systems, regardless of the billing arrangement. As a result of the adoption of Topic 606, revenue associated with the issuance of policies will be recognized upon the effective date of the associated policy, which means that commission revenues billed on an installment basis will be now recognized earlier than they had been previously resulting in revenue will accrued based upon the completion of the performance obligation and thus creating a current asset for the unbilled revenue until such time as an invoice is generated, typically not to exceed twelve months. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years.

Contingent commissions - Prior to the adoption of Topic 606, revenue that was not fixed and determinable because a contingency exists was not recognized until the contingency was resolved. Under Topic 606, the Company must use its judgment to estimate the amount of consideration that will be received such that a significant reversal of revenue is not probable. Contingent commissions represent a form of variable consideration associated with the same performance obligation, which is the placement of coverage, for which we earn core commissions. In connection with the new standard, contingent commissions will be estimated with an appropriate constraint applied and accrued relative to the recognition of the corresponding core commissions. The resulting effect on the timing of recognition of contingent commissions will more closely follow a similar pattern as our core commissions with true-ups recognized when payments are received or as additional information that affects the estimate becomes available. Contingent commissions have averaged approximately 3.6% of the previous year’s total commissions and fees over the last three years and have primarily been received in the first and second quarters of the year.

Approximately 30% of the Company’s commissions and fees is in the form of fees, which are predominantly in our National Programs and Services Segments, and to a lesser extent in the large accounts business within our Retail Segment, where we receive fees in lieu of a commission. In accordance with Topic 606, fee revenue from certain agreements will be recognized in earlier periods and others in later periods

as compared to our current accounting treatment. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years.

Additionally, the Company has evaluated ASC Topic 340 - Other Assets and Deferred Cost (“ASC 340”) which requires companies to defer certain incremental costs to obtain customer contracts, and certain costs to fulfill customer contracts.

Incremental cost to obtain - the adoption of ASC 340 will result in the Company deferring certain cost to obtain customer contracts primarily as they relate to commission based compensation plans in the Retail Segment, in which the Company pays an incremental amount of compensation on new business in the first year of the contract. These incremental costs will be deferred and amortized over a 15-year period, which is consistent with the analysis performed on acquired customer accounts and referenced in Note 4 to the Company’s financial statements.

Cost to fulfill - the adoption of ASC 340 will result in the Company deferring certain costs to fulfill a contract and recognize these costs as the associated performance obligations are fulfilled. In order for contract fulfillment costs to be deferred under ASC 340, the costs must (1) relate directly to a specific contract or anticipated contract, (2) generate or enhance resources that the Company will use in satisfying its obligations under the contract, and (3) be expected to be recovered through sufficient net cash flows from the contract. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing these expenses will be impacted among quarters to better align with the associated revenue.

Topic 606 is effective for the Company beginning January 1, 2018. Entities are permitted to adopt the guidance under one of the following methods: the “full retrospective” method, which applies the guidance to each period presented (prior years restated), or the “modified retrospective” method, in which the guidance is only applied to the year of adoption, with the cumulative effect of initially applying the guidance recognized as an adjustment to retained earnings. The Company has elected to follow the modified retrospective method applied to contracts that are not completed as of the date of adoption. The estimated cumulative impact of adopting the standard on January 1, 2018 is an increase in stockholders’ equity of between $70.0 million and $110.0 million.

In connection with the implementation of this standard, we expect to modify, and in some instances institute additional accounting procedures, processes and internal controls. Given the relative expected impacts of this standard to our revenue streams, we do not expect that these modifications and additions will materially change our internal controls over financial reporting.

Principles of Consolidation

The accompanying Consolidated Financial Statements include the accounts of Brown & Brown, Inc. and its subsidiaries. All significant intercompany account balances and transactions have been eliminated in the Consolidated Financial Statements.

Segment results for prior periods have been recast, where appropriate, to reflect the current year segmental structure. Certain reclassifications have been made to the prior year amounts reported in this Annual Report on Form 10-K in order to conform to the current year presentation.

Revenue Recognition

Commission revenues are recognized as of the effective date of the insurance policy or the date on which the policy premium is processed into our systems and invoiced to the customer, whichever is later. Commission revenues related to installment billings are recognized on the latter of effective or invoiced date, with the exception of our Arrowhead business which follows a policy of recognizing on the latter of effective or processed date into our systems, regardless of the billing arrangement. Management determines the policy cancellation reserve based upon historical cancellation experience adjusted for any known circumstances. Subsequent commission adjustments were recognized upon our receipt of notification from insurance companies concerning matters necessitating such adjustments. Profit-sharing contingent commissions are recognized when determinable, which is generally when such commissions are received from insurance companies, or when we receive formal notification of the amount of such payments. Fee revenues and commissions for workers’ compensation programs are recognized as services are rendered.

Use of Estimates

The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, as well as disclosures of contingent assets and liabilities, at the date of the Consolidated Financial Statements, and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from those estimates.

Cash and Cash Equivalents

Cash and cash equivalents principally consist of demand deposits with financial institutions and highly liquid investments with quoted market prices having maturities of three months or less when purchased.

Restricted Cash and Investments, and Premiums, Commissions and Fees Receivable

In our capacity as an insurance agent or broker, the Company typically collects premiums from insureds and, after deducting the authorized commissions, remits the net premiums to the appropriate insurance company or companies. Accordingly, as reported in the Consolidated Balance Sheets, “premiums” are receivable from insureds. Unremitted net insurance premiums are held in a fiduciary capacity until Brown & Brown disburses them. Where allowed by law, Brown & Brown invests these unremitted funds only in cash, money market accounts, tax-free variable-rate demand bonds and commercial paper held for a short term. In certain states in which Brown & Brown operates, the use and investment alternatives for these funds are regulated and restricted by various state laws and agencies. These restricted funds are reported as restricted cash and investments on the Consolidated Balance Sheets. The interest income earned on these unremitted funds, where allowed by state law, is reported as investment income in the Consolidated Statement of Income.

In other circumstances, the insurance companies collect the premiums directly from the insureds and remit the applicable commissions to Brown & Brown. Accordingly, as reported in the Consolidated Balance Sheets, “commissions” are receivables from insurance companies. “Fees” are primarily receivables due from customers.

Investments

Certificates of deposit, and other securities, having maturities of more than three months when purchased are reported at cost and are adjusted for other-than-temporary market value declines. The Company’s investment holdings include U.S. Government securities, municipal bonds, domestic corporate and foreign corporate bonds as well as short-duration fixed income funds. Investments within the portfolio or funds are held as available for sale and are carried at their fair value. Any gain/loss applicable from the fair value change is recorded, net of tax, as other comprehensive income within the equity section of the Consolidated Balance Sheet. Realized gains and losses are reported on the Consolidated Statement of Income, with the cost of securities sold determined on a specific identification basis.

Fixed Assets

Fixed assets, including leasehold improvements, are carried at cost, less accumulated depreciation and amortization. Expenditures for improvements are capitalized, and expenditures for maintenance and repairs are expensed to operations as incurred. Upon sale or retirement, the cost and related accumulated depreciation and amortization are removed from the accounts and the resulting gain or loss, if any, is reflected in other income. Depreciation has been determined using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 15 years. Leasehold improvements are amortized on the straight-line method over the shorter of the useful life of the improvement or the term of the related lease.

Goodwill and Amortizable Intangible Assets

All of our business combinations initiated after June 30, 2001 are accounted for using the acquisition method. Acquisition purchase prices are typically based upon a multiple of average annual operating profit earned over a period of 3 years within a minimum and maximum price range. The recorded purchase prices for all acquisitions consummated after January 1, 2009 include an estimation of the fair value of liabilities associated with any potential earn-out provisions. Subsequent changes in the fair value of earn-out obligations are recorded in the Consolidated Statement of Income when incurred.

The fair value of earn-out obligations is based upon the present value of the expected future payments to be made to the sellers of the acquired businesses in accordance with the provisions contained in the respective purchase agreements. In determining fair value, the acquired business’ future performance is estimated using financial projections developed by management for the acquired business and this estimate reflects market participant assumptions regarding revenue growth and/or profitability. The expected future payments are estimated on the basis of the earn-out formula and performance targets specified in each purchase agreement compared to the associated financial projections. These estimates are then discounted to present value using a risk-adjusted rate that takes into consideration the likelihood that the forecasted earn-out payments will be made.

Amortizable intangible assets are stated at cost, less accumulated amortization, and consist of purchased customer accounts and non-compete agreements. Purchased customer accounts and non-compete agreements are amortized on a straight-line basis over the related estimated lives and contract periods, which range from 3 to 15 years. Purchased customer accounts primarily consist of records and files that contain information about insurance policies and the related insured parties that are essential to policy renewals.

The excess of the purchase price of an acquisition over the fair value of the identifiable tangible and amortizable intangible assets is assigned to goodwill. While goodwill is not amortizable, it is subject to assessment at least annually, and more frequently in the presence of certain circumstances, for impairment by application of a fair value-based test. The Company compares the fair value of each reporting unit with its carrying amount to determine if there is potential impairment of goodwill. If the fair value of the reporting unit is less than its carrying value, an impairment loss is recorded to the extent that the fair value of the goodwill within the reporting unit is less than its carrying value. Fair value is estimated based upon multiples of earnings before interest, income taxes, depreciation, amortization and change in estimated acquisition earn-out payables (“EBITDAC”), or on a discounted cash flow basis. Brown & Brown completed its most recent annual assessment as of November 30, 2017 and determined that the fair value of goodwill significantly exceeded the carrying value of such assets. In addition, as of December 31, 2017, there are no accumulated impairment losses.

The carrying value of amortizable intangible assets attributable to each business or asset group comprising Brown & Brown is periodically reviewed by management to determine if there are events or changes in circumstances that would indicate that its carrying amount may not be recoverable. Accordingly, if there are any such changes in circumstances during the year, Brown & Brown assesses the carrying value of its amortizable intangible assets by considering the estimated future undiscounted cash flows generated by the corresponding business or asset group. Any impairment identified through this assessment may require that the carrying value of related amortizable intangible assets be adjusted. There were no impairments recorded for the years ended December 31, 2017, 2016 and 2015.

Income Taxes

Brown & Brown records income tax expense using the asset-and-liability method of accounting for deferred income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement carrying values and the income tax bases of Brown & Brown’s assets and liabilities.

Brown & Brown files a consolidated federal income tax return and has elected to file consolidated returns in certain states. Deferred income taxes are provided for in the Consolidated Financial Statements and relate principally to expenses charged to income for financial reporting purposes in one period and deducted for income tax purposes in other periods.

Consolidation, Policy [Policy Text Block]

Principles of Consolidation

The accompanying Consolidated Financial Statements include the accounts of Brown & Brown, Inc. and its subsidiaries. All significant intercompany account balances and transactions have been eliminated in the Consolidated Financial Statements.

Segment results for prior periods have been recast, where appropriate, to reflect the current year segmental structure. Certain reclassifications have been made to the prior year amounts reported in this Annual Report on Form 10-K in order to conform to the current year presentation.

Use of Estimates, Policy [Policy Text Block]

Use of Estimates The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, as well as disclosures of contingent assets and liabilities, at the date of the Consolidated Financial Statements, and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from those estimates

Restricted Cash and Investments Premiums Commissions and Fees Receivable Policy [Text Block]

Restricted Cash and Investments, and Premiums, Commissions and Fees Receivable

In our capacity as an insurance agent or broker, the Company typically collects premiums from insureds and, after deducting the authorized commissions, remits the net premiums to the appropriate insurance company or companies. Accordingly, as reported in the Consolidated Balance Sheets, “premiums” are receivable from insureds. Unremitted net insurance premiums are held in a fiduciary capacity until Brown & Brown disburses them. Where allowed by law, Brown & Brown invests these unremitted funds only in cash, money market accounts, tax-free variable-rate demand bonds and commercial paper held for a short term. In certain states in which Brown & Brown operates, the use and investment alternatives for these funds are regulated and restricted by various state laws and agencies. These restricted funds are reported as restricted cash and investments on the Consolidated Balance Sheets. The interest income earned on these unremitted funds, where allowed by state law, is reported as investment income in the Consolidated Statement of Income.

In other circumstances, the insurance companies collect the premiums directly from the insureds and remit the applicable commissions to Brown & Brown. Accordingly, as reported in the Consolidated Balance Sheets, “commissions” are receivables from insurance companies. “Fees” are primarily receivables due from customers.

Property, Plant and Equipment, Policy [Policy Text Block]

Fixed Assets Fixed assets, including leasehold improvements, are carried at cost, less accumulated depreciation and amortization. Expenditures for improvements are capitalized, and expenditures for maintenance and repairs are expensed to operations as incurred. Upon sale or retirement, the cost and related accumulated depreciation and amortization are removed from the accounts and the resulting gain or loss, if any, is reflected in other income. Depreciation has been determined using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 15 years. Leasehold improvements are amortized on the straight-line method over the shorter of the useful life of the improvement or the term of the related lease.

Income Tax, Policy [Policy Text Block]

Income Taxes

Brown & Brown records income tax expense using the asset-and-liability method of accounting for deferred income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement carrying values and the income tax bases of Brown & Brown’s assets and liabilities.

Brown & Brown files a consolidated federal income tax return and has elected to file consolidated returns in certain states. Deferred income taxes are provided for in the Consolidated Financial Statements and relate principally to expenses charged to income for financial reporting purposes in one period and deducted for income tax purposes in other periods.

Reinsurance Accounting Policy [Policy Text Block]

Reinsurance

The Company protects itself from claims-related losses by reinsuring all claims risk exposure. The only line of insurance the Company underwrites is flood insurance associated with the Wright National Flood Insurance Company (“WNFIC”), which is part of our National Programs Segment. However, all exposure is reinsured with the Federal Emergency Management Agency (“FEMA”) for basic admitted policies conforming to the National Flood Insurance Program. For excess flood insurance policies, all exposure is reinsured with a reinsurance carrier with an AM Best Company rating of “A” or better. Reinsurance does not legally discharge the ceding insurer from the primary liability for the full amount due under the reinsured policies. Reinsurance premiums, commissions, expense reimbursement and reserves related to ceded business are accounted for on a basis consistent with the accounting for the original policies issued and the terms of reinsurance contracts. Premiums earned and losses and loss adjustment expenses incurred are reported net of reinsurance amounts. Other underwriting expenses are shown net of earned ceding commission income. The liabilities for unpaid losses and loss adjustment expenses and unearned premiums are reported gross of ceded reinsurance recoverable.

Balances due from reinsurers on unpaid losses and loss adjustment expenses, including an estimate of such recoverables related to reserves for incurred but not reported (“IBNR”) losses, are reported as assets and are included in reinsurance recoverable even though amounts due on unpaid loss and loss adjustment expense are not recoverable from the reinsurer until such losses are paid. The Company does not believe it is exposed to any material credit risk through its reinsurance as the reinsurer is FEMA for basic admitted flood policies and a national reinsurance carrier for excess flood policies, which has an AM Best Company rating of “A” or better. Historically, no amounts due from reinsurance carriers have been written off as uncollectible.

Insurance Premiums Revenue Recognition, Policy [Policy Text Block]

PremiumsPremiums are recognized as income over the coverage period of the related policies. Unearned premiums represent the portion of premiums written that relate to the unexpired terms of the policies in force and are determined on a daily pro rata basis. The income is recorded to the commissions and fees line of the income statement.

Property, Plant and Equipment [Line Items]

Property, Plant and Equipment, Useful Life

15 years