Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Statistical Measurement Statistical Measurement [Domain] Title of 12(b) Security Title of 12(b) Security Amortization of deferred compensation and restricted stock Amortization Of Deferred Compensation And Restricted Stock Amortization of deferred compensation and restricted stock Document Fiscal Year Focus Document Fiscal Year Focus Remaining performance obligation, expected timing of satisfaction, period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Exercise Prices Range $86.17 - $86.17 Range01 [Member] Range 01 [Member] Cash paid for acquisitions, net of cash and restricted cash acquired Payments To Acquire Businesses Net Of Cash And Restricted Cash Acquired Payments to acquire businesses, net of cash and restricted cash acquired. Adjustment to Compensation, Amount Adjustment to Compensation Amount Maximum period for the exercise of stock options Period For Options To Expire From Date Of Grant Period for options to expire from date of grant. Financial Instrument Financial Instrument [Axis] Segment Reporting [Abstract] Segment Reporting [Abstract] Weighted Average Remaining Contractual Term (in years), Ending unvested and expected to vest Sharebased Compensation Arrangement By Sharebased Payment Award Options Nonvested And Expected To Vest Outstanding Weighted Average Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Options, NonVested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term. Common stock - issued and outstanding 256 shares in 2026 and 257 shares in 2025 Common Stock, Value, Issued Depreciation and amortization Depreciation, Amortization and Accretion, Net Interest Interest Expense, Operating and Nonoperating Aggregate grant-date fair value Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Fair Value Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Fair Value Senior Notes: Senior Unsecured Note [Member] Senior unsecured notes. Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Risk Management Risk Management Segment [Member] Risk Management Segment Member Restatement Determination Date Restatement Determination Date Derivative Instrument Derivative Instrument [Axis] Net funding of premium finance loans Payments for (Proceeds from) Loans Receivable Amendment Flag Amendment Flag Goodwill [Line Items] Goodwill [Line Items] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Interest paid Interest Paid, Including Capitalized Interest, Operating and Investing Activities Fixed assets Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment Contractual Obligations, Sublease Arrangement, Total Recorded Unconditional Purchase Obligation Receivable Recorded unconditional purchase obligation receivable. Weighted Average Exercise Price, Ending unvested and expected to vest (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Award Options Nonvested And Expected To Vest Exercisable Weighted Average Exercise Price Share Based Compensation Arrangement By Share Based Payment Award Options Nonvested And Expected To Vest Exercisable Weighted Average Exercise Price Credit Agreement Credit Agreement With Periodic Payments Of Interest And Principal Expires April 3 2030 [Member] Credit Agreement With Periodic Payments Of Interest And Principal Expires April 3 2030 Amortization Amortization Exercise Prices Range $228.20 - $228.20 Range06 [Member] Range 06 [Member] Noncurrent assets Business Combination, Recognized Asset Acquired, Asset, Noncurrent Non-compete agreements Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Non-Compete Agreements Business combination, recognized identifiable assets acquired and liabilities assumed, intangible assets, non-compete agreements. Purchase transaction Stock Issued During Period, Value, Acquisitions Net change in fiduciary assets and liabilities Net Change in Fiduciary Assets and Liabilities Net change in fiduciary assets and liabilities. Adjustment to consolidated statement of comprehensive earnings Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Deferred revenue recognized from business acquisitions Contract with Customer, Liability, Increase (Decrease) for Contract Acquired in Business Combination Summary of Cash, Cash Equivalents, Restricted Cash and Fiduciary Cash Schedule of Cash and Cash Equivalents [Table Text Block] Entity Address, State or Province Entity Address, State or Province Amount of Commitment Expiration by Period - 2026 Amount Of Commitment Expiration Off Balance Sheet Commitments Within Year One Amount of Commitment Expiration Off-Balance Sheet Commitments Within Year One Stock options granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Contingent revenues Contingent Revenue [Member] Contingent Revenue [Member] PEO Total Compensation Amount PEO Total Compensation Amount Foreign currency translation Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Amortizable intangible assets - net Intangible Asset, Excluding Goodwill, after Accumulated Amortization Cash and Cash Equivalents [Abstract] Cash and Cash Equivalents [Abstract] Notional amount Derivative, Notional Amount Weighted average number of common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Series I note with fixed rate of 4.73% Fixed Rate Of Four Point Seven Three Percent Balloon Due February Twenty Seven Two Thousand Twenty Six [Member] Fixed rate of four point seven three, percent balloon due February twenty seven, two thousand twenty six. Off-Balance Sheet Commitments Schedule Of Off Balance Sheet Commitments [Table Text Block] Schedule Of Off-Balance Sheet Commitments [Table Text Block] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount McKee Risk Management, Inc. May 1, 2026 (MRM) McKee Risk Management, Inc. [Member] McKee Risk Management, Inc. Number of reportable segments Number of Reportable Segments Total current liabilities Liabilities, Current Amount of Commitment Expiration by Period - 2027 Amount Of Commitment Expiration Off Balance Sheet Commitments Within Year Two Amount of Commitment Expiration Off-Balance Sheet Commitments Within Year Two Accrued compensation and other current liabilities Accrued Compensation and Other Current Liabilities Accrued compensation and other current liabilities. Entity Address, City or Town Entity Address, City or Town Investments And Employee Deferred Compensation Plan [Table] Investments And Employee Deferred Compensation Plan [Table] Investments And Employee Deferred Compensation Plan [Table] Supplemental Disclosures of Cash Flow Information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Maximum Potential Earnout Payable Maximum Potential Earnout Payable Maximum Potential Earnout Payable Shares granted in the period (in shares) Restricted stock units granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Measurement Input, Long-term Revenue Growth Rate Measurement Input, Long-Term Revenue Growth Rate [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Amortizable intangible assets - net Total Intangible Asset, Finite-Lived, after Accumulated Amortization Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Contractual Obligations, Payments Due by Period, 2030 Recorded Unconditional Purchase Obligation, to be Paid, Year Five Contractual Obligations, Payments Due by Period, Thereafter Recorded Unconditional Purchase Obligation, to be Paid, after Year Five New Zealand NEW ZEALAND Aggregate amount of maximum earnout obligations related to acquisitions, recorded in consolidated balance sheet Business Combination Aggregate Earnout Obligation Recorded Maximum Business Combination Aggregate Earnout Obligation Recorded Maximum Brokerage Brokerage Segment [Member] Brokerage Segment Member Accumulated amortization Intangible Asset, Finite-Lived, Accumulated Amortization Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Operating lease obligations Operating Lease Obligation [Member] Operating Lease Obligation [Member] Net change in period Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] United States UNITED STATES Business Acquisition Actual Revenue And Pre Tax Income Loss [Table] Business Acquisition Actual Revenue And Pre Tax Income Loss [Table] Business Acquisition Actual Revenue And Pre Tax Income Loss [Table] Change in fair value of derivative investments, net of taxes Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Debt Instrument [Table] Schedule of Long-Term Debt Instruments [Table] Business Acquisition Business Acquisition [Member] Business Acquisition [Member] Total cash and cash equivalents, restricted cash and fiduciary cash Cash and Cash Equivalents, Restricted Cash and Fiduciary Cash Cash and cash equivalents, restricted cash and fiduciary cash. Net change in deferred revenue Increase (Decrease) in Contract with Customer, Liability Grantee Status Grantee Status [Axis] Schedule of Segment Reporting Information by Segment Segment Reporting [Table Text Block] Noncontrolling Interests Noncontrolling Interest [Member] Payments on acquisition earnouts Earnout Payments For Acquisitions Earnout payments for acquisitions. Use of Estimates Use of Estimates, Policy [Policy Text Block] Aggregate amount of maximum earnout obligations related to acquisitions Business Combination Aggregate Earnout Obligation Maximum Business Combination ,Aggregate Earnout Obligation, Maximum Tax effect on net change in pension asset/liability Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Noncurrent liabilities Business Combination, Recognized Liability Assumed, Liability, Noncurrent Repayments on line of credit facility Repayments of Lines of Credit Net change in income taxes payable Increase (Decrease) in Income Taxes Payable Range of Exercise Prices, maximum (in dollars per share) Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit Current liabilities Business Combination, Recognized Liability Assumed, Liability, Current Document Period End Date Document Period End Date Business combination, initial accounting incomplete, adjustment of goodwill Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Goodwill Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Goodwill Net cash used by investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Security Exchange Name Security Exchange Name Restricted Stock and Performance Share Awards Restricted Stock And Cash Awards [Text Block] Restricted Stock and Cash Awards Number of authorized shares not disclosed Number Of Authorized Shares Not Disclosed Number Of Authorized Shares Not Disclosed Weighted Average Exercise Price, Granted (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Change in estimated acquisition earnout payables Change In Estimated Acquisition Earnout Payables Change in estimated acquisition earnout payables Valuation Approach and Technique Valuation Approach and Technique [Axis] Distributions Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Consolidation Items Consolidation Items [Domain] Sixteen other acquisitions completed in 2026 Sixteen Other Acquisitions [Member] Sixteen Other Acquisitions Contractual Obligations, Payments Due by Period, 2027 Recorded Unconditional Purchase Obligation, to be Paid, Year Two Shares authorized (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Fiduciary liabilities Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Fiduciary Liabilities Current Business combination recognized identifiable assets acquired and liabilities assumed fiduciary liabilities current. Foreign currency translation reclassified from accumulated other comprehensive earnings Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Earnings Per Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Employee Employed By AssuredPartners Employee Employed By AssuredPartners [Member] Employee Employed By AssuredPartners Long Term Incentive Plan Long Term Incentive Plan [Member] Long Term Incentive Plan [Member] Unbilled receivables Unbilled Contracts Receivable Earnings Per Share [Abstract] Earnings Per Share [Abstract] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Outstanding purchase obligations Outstanding Purchase Obligations [Member] Outstanding purchase obligations. Goodwill Business Acquisitions Purchase Price Allocation Goodwill Amount Business Acquisitions Purchase Price Allocation Goodwill Amount Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Reversal of deferred tax asset Defined Benefit Pension Plan Reversal of Deferred Tax Asset Defined Benefit Pension Plan Reversal of Deferred Tax Asset Financial guarantees Financial Guarantee [Member] Total liabilities Liabilities Trading Symbol Trading Symbol Measurement Input, Discount Rate Measurement Input, Discount Rate [Member] Thereafter Finite Lived Intangible Assets Amortization Expense After Year Four Finite-lived intangible assets, amortization expense, after year four. Geographical Geographical [Domain] Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Less unamortized debt acquisition costs and discount Debt Instrument, Unamortized Discount And Debt Issuance Expense Debt Instrument, Unamortized Discount And Debt Issuance Expense Exercise Prices Range $156.85 - $156.85 Range03 [Member] Range 03 [Member] Matching contributions by employer, percentage Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay Settlements on terminated interest rate swaps Payments For (Proceeds From) Settlements Of Terminated Interest Rate Swaps Payments for (proceeds from) settlements of terminated interest rate swaps. Company Selected Measure Name Company Selected Measure Name Total Amounts Committed Amount Of Commitment Expiration Off Balance Sheet Commitments Amount of Commitment Expiration Off-Balance Sheet Commitments Contractual Obligations, Sublease Arrangement, 2029 Recorded Unconditional Purchase Obligation Receivable In Fourth Year Recorded unconditional purchase obligation receivable in fourth year. Unearned deferred compensation, value Unearned Deferred Compensation Value Unearned Deferred Compensation, Value Pension Liability Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Other Information Regarding Stock Options Outstanding and Exercisable Share-Based Payment Arrangement, Option, Exercise Price Range [Table Text Block] Exercise Prices Range $158.56 - $161.14 Range04 [Member] Range 04 [Member] Non-Compete Agreements Noncompete Agreements [Member] Cash flows from operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Contractual Obligations, Sublease Arrangement, 2030 Recorded Unconditional Purchase Obligation Receivable In Fifth Year Recorded unconditional purchase obligation receivable in fifth year. Compensation Amount Outstanding Recovery Compensation Amount Amortization of deferred contract costs Capitalized Contract Cost, Amortization Individual: Individual [Axis] Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Total net assets acquired Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less) Net proceeds from sales of operations/books of business Net Proceeds From Sales Of Operations Net Proceeds From Sales Of Operations Underlying Security Market Price Change Underlying Security Market Price Change, Percent Supplemental revenues Supplemental Revenue [Member] Supplemental revenue. Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items] Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items] Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items] Borrowings on line of credit facility Proceeds from Lines of Credit Share-Based Payment Arrangement, Option, Exercise Price Range [Table] Share-Based Payment Arrangement, Option, Exercise Price Range [Table] Derivatives and Hedging Activity Derivative Instruments and Hedging Activities Disclosure [Text Block] Range of Exercise Prices, minimum (in dollars per share) Share-Based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit Options Exercisable, Number Exercisable (in shares) Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Corporate related borrowings - current Short-Term Debt Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Net change in other noncurrent assets and liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Award Timing Predetermined Award Timing Predetermined [Flag] Cash and cash equivalents - restricted cash Restricted Cash, Current Capital expenditures Payments for Capital Improvements Deferred Compensation Compensation Related Costs, General [Text Block] Intangible Asset, Goodwill and Other [Abstract] Intangible Asset, Goodwill and Other [Abstract] Total intrinsic value of unvested equity based awards Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Contractual Obligations, Payments Due by Period, 2028 Recorded Unconditional Purchase Obligation, to be Paid, Year Three Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Series P note with fixed rate of 4.36% Fixed Rate Of Four Point Three Six Percent Balloon Due June Twenty Four Two Thousand Twenty Six [Member] Fixed Rate Of Four Point Three Six Percent Balloon Due June Twenty Four Two Thousand Twenty Six [Member] Grantee Status Grantee Status [Domain] Dilutive effect of stock options using the treasury stock method (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Fiduciary assets Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Fiduciary Assets Current Business combination recognized identifiable assets acquired and liabilities assumed fiduciary assets current. Compensation expense related to stock option plan grants Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture Distributions Cash And Equity Award With Aggregate Fair Value Vested And Distributed To Participants Cash and equity award with aggregate fair value vested and distributed to participants. All Executive Categories All Executive Categories [Member] Employer match on eligible compensation Defined Contribution Plan, Employer Matching Contribution, Percent of Match Valuation Approach and Technique Valuation Approach and Technique [Domain] Common stock repurchases Stock Repurchased and Retired During Period, Value Valuation, Income Approach Valuation, Income Approach [Member] Deferred Compensation Arrangement Schedule of Deferred Compensation Arrangement with Individual, Share-Based Payments [Table Text Block] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Annualized revenue of business acquisitions Business Combination Annualize Revenue Business Combination, Annualize Revenue Investments And Employee Deferred Compensation Plan [Line Items] Investments And Employee Deferred Compensation Plan [Line Items] Investments And Employee Deferred Compensation Plan [Line Items] Minimum age of employee with not subject to award forfeiture on condition compliance Age Of Employee No Longer Subject To Award Forfeiture On Condition Compliance Age Of Employee No Longer Subject To Award Forfeiture On Condition Compliance Nature of Operations and Basis of Presentation Nature Of Operations And Basis Of Presentation Policy [Policy Text Block] Nature Of Operations And Basis Of Presentation Policy Policy [Text Block] Depreciation Depreciation Exercise Price Range Exercise Price Range [Domain] Plan Name Plan Name [Domain] Weighted Average Exercise Price, Beginning balance (in dollars per share) Weighted Average Exercise Price, Ending balance (in dollars per share) Option Outstanding, Weighted Average Exercise Price (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Measurement input Alternative Investment, Measurement Input Right-of-use assets Operating Lease, Right-of-Use Asset Restricted Stock Restricted Stock Units And Performance Unit Awards Restricted Stock Restricted Stock Units And Performance Unit Awards [Member] Restricted stock, restricted stock units and performance unit awards. Accounting Changes and Error Corrections [Abstract] Accounting Changes and Error Corrections [Abstract] Guarantor Obligations, Nature Guarantor Obligations, Nature [Axis] Recorded Unconditional Purchase Obligation by Category of Item Purchased Recorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Weighted average period, years Weighted Average Period Weighted Average Period Computation of Basic and Diluted Net EPS Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Fiduciary liabilities Fiduciary liabilities current Fiduciary liabilities current. Debt Instrument, Name Debt Instrument, Name [Domain] Stock Option Plans Stock Option Plans [Text Block] Stock Option Plans Text Block Shares issued to benefit plans Stock Issued During Period, Value, Employee Benefit Plan Segment Information Segment Reporting [Text Block] Minimum Minimum [Member] Dividends paid Payments of Ordinary Dividends, Common Stock Other foreign Other Foreign [Member] Other Foreign [Member] Expiration Date Trading Arrangement Expiration Date Net earnings attributable to controlling interests Business Acquisitions Pro Forma Net Income Loss To Controlling Interest Business acquisitions pro forma net income loss to controlling interest. Estimated Aggregate Amortization Expense Intangible Asset, Finite-Lived, Amortization Expense [Table Text Block] Net funding of investment transactions Payments for (Proceeds from) Investments Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Debt acquisition costs Amortization Of Debt Issuance Costs Amortization of debt issuance costs. Total stockholders' equity Beginning balance Ending balance Equity, Including Portion Attributable to Noncontrolling Interest Weighted Average Remaining Contractual Term (in years), Ending balance Option Outstanding, Weighted Average Remaining Contractual Term (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted-Average Remaining Contractual Term Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Business Combination [Line Items] Business Combination [Line Items] Shares Under Option, Exercisable at end of period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Derivative [Table] Derivative [Table] Annual Activity Of Stock Option Plans [Table] Annual Activity Of Stock Option Plans [Table] Annual Activity Of Stock Option Plans [Table] Proceeds from issuance of common stock Proceeds from Issuance of Common Stock Foreign currency translation adjustments during the period Goodwill, Foreign Currency Translation and Measurement Period Adjustments Estimated useful lives of intangibles assets, years Intangible Asset, Finite-Lived, Useful Life Accumulated Other Comprehensive Income Loss [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Contractual Obligations, Payments Due by Period, Total Recorded Unconditional Purchase Obligation Interest on debt Interest On Debt [Member] Interest On Debt [Member] Exercise Price Award Exercise Price Cash flows from investing activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Segment Reporting [Line Items] Segment Reporting [Line Items] Income (expense) related to net adjustments to estimated fair value of liability for earnout obligations Business Combination, Pro Forma Information, Pro Forma Income (Loss), after Tax Total unrecognized compensation cost related to nonvested options Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Document Quarterly Report Document Quarterly Report Wilson M. Beck Insurance Services, Inc. July 1, 2026 (WMB) Wilson M. Beck Insurance Services, Inc. [Member] Wilson M. Beck Insurance Services, Inc. Cash and cash equivalents Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Cash And Equivalents And Restricted Cash Business combination recognized identifiable assets acquired and liabilities assumed cash and equivalents and restricted cash. Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Segments Segments [Domain] Cash, cash equivalents, restricted cash and fiduciary cash at beginning of period Cash, cash equivalents, restricted cash and fiduciary cash at end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Including Discontinued Operation Lender Name Lender Name [Axis] Effect of changes in foreign exchange rates on cash, cash equivalents, restricted cash and fiduciary cash Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Including Discontinued Operation Credit and Other Debt Agreements Debt Disclosure [Text Block] Contractual Obligations, Payments Due by Period, 2029 Recorded Unconditional Purchase Obligation, to be Paid, Year Four Weighted average number of common and common equivalent shares outstanding (in shares) Weighted Average Number Of Common And Common Equivalent Shares Outstanding Weighted Average Number Of Common And Common Equivalent Shares Outstanding Letters of credit Letters Of Credit [Member] Letters Of Credit [Member] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Business Combination [Table] Business Combination [Table] Equity Component Equity Component [Domain] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Deferred Revenue Arrangement By Type [Table] Deferred Revenue Arrangement, by Type [Table] Measurement Input Type Measurement Input Type [Domain] Foreign Exchange Contract Foreign Exchange Contract [Member] Interest income, premium finance revenues and other income Investment Performance [Member] Brokerage Management Insurance Brokerage Management Services [Member] Insurance brokerage management services. Recorded Unconditional Purchase Obligation, Category Recorded Unconditional Purchase Obligation, Category [Domain] Total expenses Costs and Expenses Adoption Date Trading Arrangement Adoption Date Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Table] Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Table] Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Table] Deferred Cash Participation Plan (DCPP) Deferred Cash Participation Plan [Member] Deferred Cash Participation Plan [Member] Interest rate Debt Instrument, Interest Rate, Stated Percentage W.N. Tuscano Agency, Inc. July 1, 2026 (WNT) W.N. Tuscano Agency, Inc. [Member] W.N. Tuscano Agency, Inc. Cash dividends declared on common stock Dividends, Common Stock, Cash Stockholders' equity attributable to controlling interests Equity, Attributable to Parent Defined benefit plan, non-cash, pre-tax loss due to plan termination Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement Exercise Prices Range $337.74 - $347.74 Range08 [Member] Range 08. Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Common Shares Issued (in shares) Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares Accounting Policies [Abstract] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Estimated pretax gain to be reclassified from accumulated other comprehensive loss into earnings Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred Expected risk-free interest rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Contractual Obligations, Sublease Arrangement, 2027 Recorded Unconditional Purchase Obligation Receivable In Second Year Recorded unconditional purchase obligation receivable in second year. Insider Trading Policies and Procedures [Line Items] Shares Under Option, Beginning balance (in shares) Shares Under Option, Ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Goodwill true-ups due to appraisals and other acquisition adjustments (see Note 3) Goodwill, Measurement Period Adjustment Business acquisition not deductible for income tax purposes Business Acquisition Purchase Price Allocation Goodwill Not Expected Tax Deductible Amount Business Acquisition Purchase Price Allocation Goodwill Not Expected Tax Deductible Amount Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Performance Shares Performance Shares [Member] Provision for deferred income taxes Deferred Income Tax Expense (Benefit) Repayments of debt Repayments of Debt Business Combination Business Combination [Domain] Percentage of eligible compensation for matching contributions by employer Defined Benefit Plan Percentage Of Eligible Compensation For Matching Contributions By Employer Defined benefit plan percentage of eligible compensation for matching contributions by employer. Black-Scholes Option Pricing Model Black Scholes Option Pricing Model [Member] Black-Scholes Option Pricing Model [Member] Commitments, Contingencies and Off-Balance Sheet Arrangements Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Anti-dilutive stock-based awards shares outstanding (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Premium Financing Debt Facility Premium Financing Debt Facility [Member] Premium Financing Debt Facility [Member] Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Changes in Carrying Amount of Goodwill Goodwill [Table Text Block] Entity Central Index Key Entity Central Index Key Capital in excess of par value Additional Paid in Capital, Common Stock All Adjustments to Compensation All Adjustments to Compensation [Member] Business Combination Business Combination [Axis] Equity [Abstract] Equity [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Stockholders' equity: Equity, Attributable to Parent [Abstract] Income Statement [Abstract] Income Statement [Abstract] Employee stock purchase plan (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Document Transition Report Document Transition Report Net gain on investments and other Gain (Loss) on Investments Deferred income taxes Deferred Income Tax Assets, Net Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Major Classes of Amortizable Intangible Assets Intangible Asset, Finite-Lived [Table Text Block] Diluted net earnings per share (in dollars per share) Business Combination, Pro Forma Information, Pro Forma Earnings Per Share, Diluted Black-Scholes Option Pricing Model with Weighted Average Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Deferred revenue - current Deferred Revenue, Current Shares Under Option Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Other current assets Business Combination, Recognized Asset Acquired, Other Asset, Current City Area Code City Area Code Fiduciary assets (includes fiduciary cash of $7,596 in 2026 and $7,142 in 2025) Fiduciary assets current Fiduciary assets current. Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Corporate Corporate Segment [Member] Impact of change in foreign exchange rates Contract With Customer Impact Of Change In Foreign Exchange Rates Contract with customer impact of change in foreign exchange rates. Credit Agreement Credit Agreement [Member] Credit Agreement [Member] Name Forgone Recovery, Individual Name Aggregate Intrinsic Value, Ending Balance Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, aggregate Intrinsic Value Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Common Shares Value Business Combination, Consideration Transferred, Equity Interest Statement [Line Items] Statement [Line Items] Total assets Assets Assets Defined Benefit Plan [Table] Defined Benefit Plan [Table] Business Combination [Abstract] Business Combination [Abstract] Note Purchase Agreements Note Purchase Agreement [Member] Note Purchase Agreement [Member] Operating Segments Operating Segments [Member] Weighted average fair value per option for all options (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Amount of Commitment Expiration by Period - 2030 Amount Of Commitment Expiration Off Balance Sheet Commitments Within Year Five Amount of Commitment Expiration Off-Balance Sheet Commitments Within Year Five Awards approved and contributed to rabbi trust Compensation Approved By Committee Value Compensation approved by committee, value Total liabilities assumed Business Combination, Recognized Liability Assumed, Liability Employee stock purchase plan Stock Issued During Period, Value, Employee Stock Purchase Plan Long-term Purchase Commitment, Category of Item Purchased Long-Term Purchase Commitment, Category of Item Purchased [Domain] Net change in other current assets Increase (Decrease) in Other Operating Assets Stock issuance from public offering (in shares) Stock Issued During Period, Shares, New Issues PEO PEO [Member] Net corporate and other debt Debt, Long-Term and Short-Term, Combined Amount Cash and Cash Equivalents Cash and Cash Equivalents [Domain] Contractual Obligations, Sublease Arrangement, 2026 Recorded Unconditional Purchase Obligation Receivable Within One Year Recorded unconditional purchase obligation receivable within one year. Compensation expense recognized Share-Based Payment Arrangement, Expense Common stock repurchases (in shares) Stock Repurchased and Retired During Period, Shares Unearned deferred compensation, shares (in shares) Unearned Deferred Compensation Share Unearned Deferred Compensation, Shares Other noncurrent liabilities (includes tax credit carryforwards of $XXX in 2026 and $713 in 2025) Other Liabilities, Noncurrent Deferred Equity Participation Plan (DEPP) Deferred Equity Participation Plan [Member] Deferred equity participation plan. Goodwill Total goodwill Beginning Balance Ending Balance Goodwill Retirement Plan Type Retirement Plan Type [Axis] Provisional performance share awards approved (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized Net purchase of subsidiary shares from noncontrolling interests Minority Interest Increase Decrease From Redemptions Minority interest increase decrease from redemptions. Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Goodwill acquired during the period Goodwill, Acquired During Period Stock option plans (in shares) Shares Under Option, Exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Aggregate approval-date fair value Share Based Compensation Arrangement By Share Based Payment Award Aggregate Fair Value Share Based Compensation Arrangement By Share Based Payment Award Aggregate Fair Value Revenue recognized during the nine-month period ended September 30, 2026 included in deferred revenue at December 31, 2025 Contract with Customer, Liability, Revenue Recognized Fees Broker Fees [Member] Broker Fees [Member] Incremental deferred revenue Contract With Customer Liability Additions Contract with customer, liability, additions. 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Accrued Liability Business Combination Recognized Identifiable Assets Acquired And Liabilities Accrued Liability Business combination recognized identifiable assets acquired and liabilities accrued liability. 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Weighted Average Exercise Price, Forfeited or canceled (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Purchase transactions (in shares) Stock Issued During Period, Shares, Acquisitions Exercise Price Range Exercise Price Range [Axis] Exercise Prices Range $238.88 - $243.54 Range07 [Member] Range 07 [Member] Schedule Of Segment Reporting Information By Segment [Table] Segment Reporting [Table] Shares available for grant (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Contractual Obligations, Sublease Arrangement, 2028 Recorded Unconditional Purchase Obligation Receivable In Third Year Recorded unconditional purchase obligation receivable in third year. 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Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Change in pension liability, net of taxes Change in pension liability, net of taxes Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Exercise Prices Range $127.90 - $127.90 Range02 [Member] Range 02 [Member] Other noncurrent assets Other Assets, Noncurrent Line of Credit Facility, Lender Line of Credit Facility, Lender [Domain] Document Type Document Type Fair Value as of Grant Date Award Grant Date Fair Value Matching contributions vesting schedule Matching Contributions Vesting Schedule Matching contributions vesting schedule. 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Expiration lists Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Expiration Lists Business combination, recognized identifiable assets acquired and liabilities assumed, intangible assets, expiration lists. Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] 2030 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Four Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Vesting period, years Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Goodwill [Roll Forward] Goodwill [Roll Forward] Number of purchase transactions Stock Issued During Period, Acquisition, Number Of Purchase Transactions Stock Issued During Period, Acquisition, Number Of Purchase Transactions Australia AUSTRALIA Intangible Asset, Finite-Lived, Class Intangible Asset, Finite-Lived, Class [Domain] Weighted Average Remaining Contractual Term (in years), Exercisable at end of year Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted-Average Remaining Contractual Term Business combination, earnout payable evaluation period Business Combination, Contingent Consideration, Liability, Measurement Period Business Combination, Contingent Consideration, Liability, Measurement Period Trade Names Trade Names [Member] All Award Types Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Expected life (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term 2027 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year One Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] PEO Name PEO Name Carrying Amount of Goodwill Allocated by Domestic and Foreign Operations Carrying Amount Of Goodwill Allocated By Domestic And Foreign Operations [Table Text Block] Carrying Amount of Goodwill Allocated by Domestic and Foreign Operations Geographical Geographical [Axis] Deferred contract costs Deferred revenue beginning balance Deferred revenue ending balance Contract with Customer, Liability Fair Value of Derivative Investments Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Series II note with fixed rate of 4.85% Fixed Rates Of Four Point Eight Five Percent Balloon Due February Thirteen Two Thousand Twenty Six [Member] Fixed rates of four point eight five percent balloon due February thirteen two thousand twenty six. Entity Tax Identification Number Entity Tax Identification Number Net change in accrued compensation and other accrued liabilities Net Change In Accrued Compensation And Other Accrued Liabilities Net change in accrued compensation and other accrued liabilities Net change in collected billings/deposits received from customers Net Change In Collected Billings And Deposits Received From Customers Net change in collected billings and deposits received from customers. Option Exercisable, Weighted Average Exercise Price (in dollars per share) Share-Based Payment Arrangement, Option, Exercise Price Range, Exercisable, Weighted Average Exercise Price Weighted Average Exercise Price, Exercised (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Cash and cash equivalents Total cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Intangible Asset, Finite-Lived [Table] Intangible Asset, Finite-Lived [Table] Aggregate amount of earnout obligation expected settlement in cash or stock at option Business Combination Aggregate Earnout Obligation Expected Settlement In Cash Or Stock At Option Business combination aggregate earnout obligation expected settlement in cash or stock at option. 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Tax credit carryforwards Deferred Tax Assets, Tax Credit Carryforwards Trade names Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Trade Names Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Trade Names Summary of Corporate and Other Debt Schedule of Debt [Table Text Block] Long-term Debt, Type Long-Term Debt, Type [Domain] Basic net earnings per share (in dollars per share) Earnings Per Share, Basic Measurement Input Type Measurement Input Type [Axis] Stock Option Granted and Stock Option Compensation Expense Disclosure of Share-Based Compensation Arrangements by Share-Based Payment Award [Table Text Block] Repurchases of common stock Payments for Repurchase of Common Stock Total current assets Assets, Current Change in Contract with Customer, Liability [Roll Forward] Change in Contract with Customer, Liability [Roll Forward] Change in Contract with Customer, Liability Statistical Measurement Statistical Measurement [Axis] Insider Trading Arrangements [Line Items] Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items] Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items] Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items] Corporate related borrowings - noncurrent Long-Term Debt, Excluding Current Maturities Award Type Award Type [Axis] Interest Rate Contract Interest Rate Contract [Member] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Accounts receivable, net Accounts Receivable, after Allowance for Credit Loss, Current Krose GmbH & Co KG February 25, 2026 (KGC) Krose GmbH & Co KG [Member] Krose GmbH & Co KG Summary of Estimated Fair Values of Net Assets Acquired Schedule Of Business Acquisition Acquisition Of Assets [Table Text Block] Schedule Of Business Acquisition, Acquisition of assets [Text Block] Retained earnings Retained Earnings (Accumulated Deficit) Product and Service Product and Service [Axis] Change in fair value of derivative instruments, net of taxes Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent Payments on acquisition earnouts in excess of original estimates Business Combination, Contingent Consideration, Change in Contingent Consideration, Liability, Increase (Decrease) Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Common Stock Common Stock [Member] Volatility Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Net borrowings of corporate related long-term debt Proceeds From Repayments of Corporate Related Long Term Debt Proceeds from repayments of corporate related long-term debt. Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Cover [Abstract] Expected dividend yield Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate Total cash, cash equivalents, restricted cash and fiduciary cash Cash, cash equivalents, restricted cash and fiduciary cash Cash, cash equivalents, restricted cash and fiduciary cash. United Kingdom UNITED KINGDOM Net borrowings on premium financing debt facility Net Borrowings Payments On Premium Financing Debt Facility Net borrowings (payments) on premium financing debt facility. 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Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Valuation, Market Approach Valuation, Market Approach [Member] Recorded Earnout Payable Recorded Earn Out Payable Recorded Earnout Payable Adjustment to Compensation: Adjustment to Compensation [Axis] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Premium financing debt Premium Financing Borrowings Premium financing borrowings. Amount of Commitment Expiration by Period - Thereafter Amount Of Commitment Expiration Off Balance Sheet Commitments Within Year Thereafter Amount of Commitment Expiration Off-Balance Sheet Commitments Within Year Thereafter Total Recorded Purchase Price Business Acquisition Cost Of Acquired Entity Purchase Price Net Business Acquisition Cost Of Acquired Entity Purchase Price Net Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Name Measure Name Performance Share Award Activity under the LTIP Share-Based Compensation Arrangements by Share-Based Payment Award, Performance-Based Units, Vested and Expected to Vest [Table Text Block] Pay vs Performance Disclosure [Line Items] Reimbursements Revenue From Contract With Customer Excluding Assessed Tax Reimbursements Revenue from contract with customer excluding assessed tax reimbursements. Cash and cash equivalents - non-restricted cash Cash And Cash Equivalents Excluding Restricted Cash Cash and cash equivalents excluding restricted cash. Shares issued to benefit plans (in shares) Stock Issued During Period, Shares, Employee Benefit Plan Debt Instrument [Line Items] Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Gross consideration Business Combination, Consideration Transferred Apollo Insurance Solutions Ltd. August 1, 2026 (APO) Apollo Insurance Solutions Ltd. [Member] Apollo Insurance Solutions Ltd. 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Statement [Table] Statement [Table] Restatement Determination Date: Restatement Determination Date [Axis] Employee Employed By Gallagher Former AssuredPartners Employee, Employed With Gallagher [Member] Former AssuredPartners Employee, Employed With Gallagher Reimbursements Cost Reimbursements Cost reimbursements. Schedule of Accumulated Other Comprehensive Loss Attributable to Controlling Interests Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Deferred compensation and restricted stock (in shares) Stock Issued During Period Shares Deferred Compensation And Restricted Stock Stock issued during period, shares, deferred compensation and restricted stock. 2026 Acquisitions Two Thousand Twenty Six Acquisitions [Member] Two Thousand Twenty Five Acquisitions. Summary of Expected Revenue Related to Performance Obligations Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Weighted Average Exercise Price, Exercisable at end of period (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Summary of Unbilled Receivables, Contract Assets and Contract Liabilities from Contracts with Customers Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Share-Based Payment Arrangement, Option, Exercise Price Range [Line Items] Cash and Cash Equivalents Cash and Cash Equivalents [Axis] Effect of changes in foreign exchange rates Unrealized Gain (Loss), Foreign Currency Transaction, before Tax 2025 Acquisitions Two Thousand Twenty Five Acquisitions [Member] Two Thousand Twenty Four Acquisitions. 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