Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Andersen Aggregator LLC Andersen Aggregator LLC [Member] Andersen Aggregator LLC Statistical Measurement [Domain] Statistical Measurement [Domain] Amortized cost Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date [Abstract] Award Timing Predetermined Award Timing Predetermined [Flag] Related Party Transaction [Axis] Related Party Transaction [Axis] Entity File Number Entity File Number Additional Paid-in-Capital Additional Paid-in Capital [Member] IPO IPO [Member] Tabular List, Table Tabular List [Table Text Block] Unbilled services Unbilled Contracts Receivable Recently Issued Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] Post-service obligation payment period Post-Service Obligation Payment Period Post-Service Obligation Payment Period Thereafter Purchase Obligation, To Be Paid, After Year Four Purchase Obligation, To Be Paid, After Year Four Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Net income per share of Class A common stock, basic (in dollars per share) Earnings per share attributable to Class A common stockholders, basic (in dollars per share) Earnings Per Share, Basic Adjustment to Compensation: Adjustment to Compensation [Axis] Transactions with Related Parties Related Party Transactions Disclosure [Text Block] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Accounts payable and other accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Common stock reserved for issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Revenue Revenue from Contract with Customer [Text Block] Stock, Class of Stock [Table] Stock, Class of Stock [Table] Schedule of Reportable Operating Segment Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Total held-to-maturity securities Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain Adjustment to Compensation, Amount Adjustment to Compensation Amount Andersen Group Inc Andersen Group Inc [Member] Andersen Group Inc Equity-based compensation Share-Based Payment Arrangement, Noncash Expense Employee Stock Option Share-Based Payment Arrangement, Option [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Total loans and notes receivable from related parties, net of allowance for credit losses Total loans and notes receivable from related parties, net of allowance for credit losses Financing Receivable, after Allowance for Credit Loss Total stockholders' deficit attributable to Andersen Group Inc. Equity, Attributable to Parent Measurement Frequency [Axis] Measurement Frequency [Axis] Insider Trading Policies and Procedures [Line Items] Compensation expenses Total Share-Based Payment Arrangement, Expense Schedule of Property and Equipment Property, Plant and Equipment [Table Text Block] Common stock authorized (in shares) Common Stock, Shares Authorized Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Deferred Compensation Arrangement with Individual, Excluding Share-Based Payment and Postretirement Benefit [Table] Deferred Compensation Arrangement with Individual, Excluding Share-Based Payment and Postretirement Benefit [Table] Goodwill and Intangible Assets Disclosure [Abstract] Current assets: Assets, Current [Abstract] Total liabilities, redeemable noncontrolling interest and stockholders' equity Liabilities and Equity Other current liabilities Increase (Decrease) in Other Current Liabilities Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Fair Value, Recurring Fair Value, Recurring [Member] If Balance Is Less Than $550,000 If Balance Is Less Than $550,000 [Member] If Balance Is Less Than $550,000 Net income Temporary Equity, Net Income Liabilities, redeemable noncontrolling interest and stockholders' equity (deficit) Liabilities and Equity [Abstract] Cover [Abstract] Cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Common unit, outstanding (in shares) Common Unit, Outstanding Maximum Maximum [Member] Useful life Finite-Lived Intangible Asset, Useful Life 2029 Purchase Obligation, to be Paid, Year Three Less: net income attributable to noncontrolling interest Net income attributable to noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Accounting Policies [Abstract] Net Intangible assets Finite-Lived Intangible Assets, Net Revenue Recognition and Deferred Revenue [Abstract] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount AT Umbrella LLC LTIP Units AT Umbrella LLC LTIP Units [Member] AT Umbrella LLC LTIP Units Debt Instrument [Line Items] Debt Instrument [Line Items] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] East US East Region [Member] AT Umbrella LLC AT Umbrella LLC [Member] AT Umbrella LLC Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Training Center Agreement Training Center Agreement [Member] Training Center Agreement Andersen Aggregator LLC On Behalf of Directors Andersen Aggregator LLC On Behalf of Directors [Member] Andersen Aggregator LLC On Behalf of Directors Number of votes Common Stock, Number Of Votes Common Stock, Number Of Votes Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Income before income tax expense Pre-tax income Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Forfeiture of Class X Umbrella Units and corresponding cancellation of Class B common stock Temporary Equity, Share Forfeitures and Expirations, Amount Temporary Equity, Share Forfeitures and Expirations, Amount Other liabilities Other Liabilities, Noncurrent Schedule of Long-Term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] License Fees and Andersen Global Commitments License Fees and Andersen Global Commitments [Member] License Fees and Andersen Global Commitments Statement of Stockholders' Equity [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Other liabilities Increase (Decrease) in Other Noncurrent Liabilities Due within one year or less Debt Securities, Held-to-Maturity, Unrealized Loss, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One Debt Securities, Held-to-Maturity, Unrealized Loss, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One Due within one year or less Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One Name Measure Name Schedule of Equity-based Compensation Expense Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Operating lease liabilities, current Operating Lease, Liability, Current Class of Stock [Line Items] Class of Stock [Line Items] Capitalized internal use software Software and Software Development Costs [Member] Document Fiscal Period Focus Document Fiscal Period Focus Issuance of threshold (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Issuance Of Threshold Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Issuance Of Threshold Award Timing Method Award Timing Method [Text Block] Effect of dilutive LTIP Units (in shares) Incremental Common Shares Attributable to Dilutive Effect of Equity Unit Purchase Agreements Furniture and fixtures Furniture and Fixtures [Member] Award Type Award Type [Axis] 2025 Equity Incentive Plan 2025 Equity Incentive Plan [Member] 2025 Equity Incentive Plan Total Long-Term Debt Financing Receivable, after Allowance for Credit Loss, Current, Related Party [Extensible Enumeration] Financing Receivable, after Allowance for Credit Loss, Current, Related Party [Extensible Enumeration] Legal Entity [Axis] Legal Entity [Axis] Total assets Assets Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Investment, Name [Domain] Investment, Name [Domain] 2027 Finite-Lived Intangible Asset, Expected Amortization, Year One Trading Symbol Trading Symbol Principal balance, threshold Debt Instrument, Principal Balance, Threshold Debt Instrument, Principal Balance, Threshold Geographical [Domain] Geographical [Domain] Business Tax Services Business Tax Services [Member] Business Tax Services Membership interest units acquired (in shares) Membership Interest Units Acquired Membership Interest Units Acquired Members' Equity Member Units [Member] Loans and notes receivable from related parties Financing Receivable, Allowance for Credit Loss [Roll Forward] Financing Receivable, Allowance for Credit Loss [Roll Forward] Entity Address, City or Town Entity Address, City or Town Cash flows from operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Intangible Assets, Net Intangible Assets Disclosure [Text Block] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Statement of Income Location, Balance [Domain] Statement of Income Location, Balance [Domain] Amortized Intangible Assets, Excluding Software In Development Amortized Intangible Assets, Excluding Software In Development [Member] Amortized Intangible Assets, Excluding Software In Development Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Notes payable to related parties, less current portion Notes Payable, Noncurrent Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Due between one and two years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, Between Year One And Two Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, Between Year One And Two Entity Emerging Growth Company Entity Emerging Growth Company 2029 Long-Term Debt, Maturity, Year Three Total held-to-maturity securities Debt Securities, Held-to-Maturity, Fair Value Variable Interest Entity Consolidation, Variable Interest Entity, Policy [Policy Text Block] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Schedule of Investments in Held to Maturity Debt Securities Debt Securities, Held-to-Maturity [Table Text Block] Right-of-use assets obtained in exchange for lease liabilities (including remeasurements) Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Accounts receivable Billed Contracts Receivable Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Reserves related to receivables Allowance for Doubtful Accounts, Premiums and Other Receivables Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Related Party Related Party [Member] Distributions paid Distributions paid Payments of Distributions to Affiliates Common stock, shares, outstanding (in shares) Common Stock, Shares, Outstanding Provision for credit losses on accounts receivable Addition to / (reduction in) provision Accounts Receivable, Credit Loss Expense (Reversal) Unrealized losses Debt Securities, Held-to-Maturity, Unrealized Loss, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date [Abstract] Debt Securities, Held-to-Maturity, Unrealized Loss, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date Total held-to-maturity securities Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss Plan Name [Axis] Plan Name [Axis] PEO PEO [Member] Accounts Receivable, Net Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] TRA Parties TRA Parties [Member] TRA Parties Interest income Investment Income, Interest Deferred compensation expenses Deferred Compensation Arrangement with Individual, Compensation Expense Income tax payable Accrued Income Taxes, Current Changes in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [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] Due between one and two years Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Between Year One And Two Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Between Year One And Two Number of service lines Number of Service Lines Number of Service Lines Nature of Operation, Product Information, Concentration of Risk [Table] Nature of Operation, Product Information, Concentration of Risk [Table] Schedule of Estimated Future Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Undistributed Earnings and Accumulated Deficit Retained Earnings [Member] Prepaid expenses and other current assets Total prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Number of Units Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Share-Based Payment Arrangement [Abstract] Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income tax expense Income tax provision Income Tax Expense (Benefit) Class B Common Stock Common Class B [Member] Sale of Stock [Domain] Sale of Stock [Domain] Fair Value, Nonrecurring Fair Value, Nonrecurring [Member] If Balance Is At Least $550,000 If Balance Is At Least $550,000 [Member] If Balance Is At Least $550,000 Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Product and Service [Domain] Product and Service [Domain] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Due within one year or less Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Parent Parent [Member] Net income Net income Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Notes Payable Notes Payable, Other Payables [Member] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Less: accumulated depreciation and amortization Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, Accumulated Depreciation and Amortization City Area Code City Area Code Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Beginning balance (in shares) Ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Commitments and Contingencies Disclosure [Abstract] Cash flows from investing activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Net cash (used in) provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Thereafter Long-Term Debt, Maturity, After Year Four Long-Term Debt, Maturity, After Year Four Defined contribution plan, percent of match Defined Contribution Plan, Employer Matching Contribution, Percent of Match Debt instrument, term Debt Instrument, Term Related Party Transactions [Abstract] Preferred stock par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Subsequent Event Subsequent Event [Member] Sales, general and administrative Selling, General and Administrative Expenses [Member] Cost of services Cost of Sales [Member] Goodwill Goodwill Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Depreciation and amortization expense Depreciation Long-Term Debt, Type [Axis] Long-Term Debt, Type [Axis] Remainder of 2026 Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year Numerator: Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] Equity Components [Axis] Equity Components [Axis] Entity Ex Transition Period Entity Ex Transition Period Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Standby Letters of Credit Standby Letters of Credit [Member] Organization and Business Description Nature of Operations [Text Block] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Operating expenses: Operating Costs and Expenses [Abstract] Valuation Services Valuation Services [Member] Valuation Services Number of reportable segments Number of Reportable Segments Triggering Event [Axis] Triggering Event [Axis] Triggering Event Other Performance Measure, Amount Other Performance Measure, Amount Central US Central Region [Member] US Central Region Investments in held-to-maturity debt securities, current Debt Securities, Held-to-Maturity, Excluding Accrued Interest, after Allowance for Credit Loss, Current Entity Address, State or Province Entity Address, State or Province Fixed Bonus Percentage Based on Revenues Generated Fixed Bonus Percentage Based on Revenues Generated [Member] Fixed Bonus Percentage Based on Revenues Generated Principal payments under finance lease obligations Finance Lease, Principal Payments Antidilutive Security, Excluded EPS Calculation [Table] Antidilutive Security, Excluded EPS Calculation [Table] Related and Nonrelated Parties [Domain] Related and Nonrelated Parties [Domain] Distributions Distributions to pre-IPO owners Dividends Total current liabilities Liabilities, Current Over-Allotment Option Over-Allotment Option [Member] Net change in cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Excluding Exchange Rate Effect, Including Discontinued Operation Employee Compensation and Benefits Compensation Related Costs, General [Text Block] Individual: Individual [Axis] Triggering Event [Domain] Triggering Event [Domain] Triggering Event [Domain] Total matching contributions Defined Contribution Plan, Cost Total property and equipment Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization Other current assets Other Assets, Current Property and equipment acquired through finance leases Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Entities [Table] Entities [Table] Entity [Domain] Entity [Domain] Net cash (used in) provided by investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation 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] 2027 Purchase Obligation, to be Paid, Year One Document Fiscal Year Focus Document Fiscal Year Focus Loss exposure, amount Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Pre-paid capital and debt obligation Repayments of Long-Term Debt Loans and notes receivable from related parties, net of allowance for credit losses of $2,659 and $2,513, respectively Financing Receivable, after Allowance for Credit Loss, Current Effective tax rate Effective Income Tax Rate Reconciliation, Percent Entity Interactive Data Current Entity Interactive Data Current Plan Name [Domain] Plan Name [Domain] Weighted-average period cost not yet recognized Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Fair value Debt Securities, Held-to-Maturity, Fair Value, Maturity [Abstract] Equity [Abstract] Member firm loans Member Firm Loans [Member] Member Firm Loans Deferred compensation term (in years) Deferred Compensation Arrangement with Individual, Requisite Service Period Amounts Payable to Related Parties Pursuant to Tax Receivable Agreement Payable to Related Parties Pursuant to Tax Receivable Agreement [Policy Text Block] Payable to Related Parties Pursuant to Tax Receivable Agreement Total Purchase Obligation West US West Region [Member] Segment Reporting Segment Reporting Disclosure [Text Block] Due within one year or less Debt Securities, Held-to-Maturity, Unrealized Gain, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One Debt Securities, Held-to-Maturity, Unrealized Gain, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Distribution Temporary Equity, Decrease From Distribution Temporary Equity, Decrease From Distribution Loans and notes receivable from related parties, allowance for credit loss Financing Receivable, Allowance for Credit Loss, Current Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Axis] Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Ownership [Domain] Ownership [Domain] Schedule of Minimum Payments Other Commitments [Table Text Block] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Amortization expense Amortization of Intangible Assets Gross amount of office equipment under finance leases, accumulated amortization Finance Lease, Right-of-Use Asset, Accumulated Amortization Sales, general and administrative Sales, general and administrative expenses Selling, General and Administrative Expense Depreciation and amortization Depreciation, Depletion and Amortization Other assets Other Assets, Noncurrent Loans and notes receivable from related parties, net of allowance for credit losses of $8,076 and $8,222, respectively Financing Receivable, after Allowance for Credit Loss, Noncurrent Entity Central Index Key Entity Central Index Key PEO Name PEO Name Schedule of Future Maturities of Long-Term Debt Schedule of Maturities of Long-Term Debt [Table Text Block] 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] 2028 Purchase Obligation, to be Paid, Year Two Trademark and License Fees Trademark and License Fees [Member] Trademark and License Fees Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Revolving Credit Facility Revolving Credit Facility [Member] Arrangement Duration Trading Arrangement Duration Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Computer equipment Computer Equipment [Member] Financial Instruments and Fair Value Measurements Financial Instruments Disclosure [Text Block] Deferred revenue Contract with Customer, Liability, Current Segments [Axis] Segments [Axis] Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Exercise Price Award Exercise Price Andersen Global Commitments Andersen Global Commitments [Member] Andersen Global Commitments Anderson Group Inc Anderson Group Inc [Member] Anderson Group Inc Entity Filer Category Entity Filer Category Local Phone Number Local Phone Number Class of Stock Class of Stock [Domain] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Unamortized compensation cost not yet recognized Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Subsequent Event Type [Axis] Subsequent Event Type [Axis] Equity-Based Compensation Share-Based Payment Arrangement [Text Block] Carrying amount Variable Interest Entity, Nonconsolidated, Comparison of Carrying Amount of Assets and Liabilities to Maximum Loss Exposure Assets Assets [Abstract] Credit Facility [Axis] Credit Facility [Axis] Nonrelated Party Nonrelated Party [Member] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Other Commitments [Axis] Other Commitments [Axis] Total loans and notes receivable from related parties Financing receivable, before allowance for credit loss Financing Receivable, before Allowance for Credit Loss Debt Instrument [Axis] Debt Instrument [Axis] Financial Instruments and Fair Value Measurements Fair Value Disclosures [Text Block] Non-cash lease expense Non-cash Operating Lease, Expense Non-cash Operating Lease, Expense Credit Facility [Domain] Credit Facility [Domain] Gross Carrying Value Finite-Lived Intangible Assets, Gross Stockholders' equity (deficit): Equity, Attributable to Parent [Abstract] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Vesting percentage Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage Number of states Number of States in which Entity Operates Entity Address, Address Line One Entity Address, Address Line One Beginning Balance Ending Balance Temporary Equity, Including Noncontrolling Interest Entity Address, Address Line Two Entity Address, Address Line Two Forfeiture of Class X Umbrella Units and corresponding cancellation of Class B common stock (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Forfeitures and Expirations Interest rate Debt Instrument, Interest Rate, Stated Percentage Investment, Name [Axis] Investment, Name [Axis] Accounts receivable, allowance for credit loss Accounts Receivable, Allowance for Credit Loss, Current Operating lease liabilities, noncurrent Operating Lease, Liability, Noncurrent Redeemable noncontrolling interest (Note 11) Redeemable Noncontrolling Interest, Equity, Carrying Amount Ownership [Axis] Ownership [Axis] Unrealized gains Debt Securities, Held-to-Maturity, Unrealized Gain, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date [Abstract] Debt Securities, Held-to-Maturity, Unrealized Gain, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date Fair Value as of Grant Date Award Grant Date Fair Value Total accounts receivable, net Accounts Receivable, after Allowance for Credit Loss Property, Plant and Equipment [Abstract] Entity Registrant Name Entity Registrant Name Other assets Increase (Decrease) in Other Noncurrent Assets Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Software In Development Software In Development [Member] Software In Development Due between one and two years Debt Securities, Held-to-Maturity, Unrealized Gain, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Between Year One And Two Debt Securities, Held-to-Maturity, Unrealized Gain, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Between Year One And Two Personnel costs Labor and Related Expense Deferred Bonus and Profit Sharing Arrangement, Individual Contract, Type of Deferred Compensation [Domain] Deferred Bonus and Profit Sharing Arrangement, Individual Contract, Type of Deferred Compensation [Domain] Floor interest rate (as percent) Debt Instrument, Floor Interest Rate Debt Instrument, Floor Interest Rate Effect of dilutive RSUs (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Share issued (in shares) Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Total operating expenses Costs and Expenses Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Related Party Transaction [Line Items] Related Party Transaction [Line Items] Document Quarterly Report Document Quarterly Report Schedule of Outstanding Award, Activity, Excluding Option Share-Based Payment Arrangement, Outstanding Award, Activity, Excluding Option [Table Text Block] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Granted Counterparty Name [Domain] Counterparty Name [Domain] Number of offices Number Of Offices In Which Entity Operates Number Of Offices In Which Entity Operates Number of operating segments Number of Operating Segments Amortization of discount on held-to-maturity debt securities Accretion (Amortization) of Discounts and Premiums, Investments Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Notes Payable, Noncurrent, Related Party [Extensible Enumeration] Notes Payable, Noncurrent, Related Party [Extensible Enumeration] Supplemental Balance Sheet Disclosures [Line Items] Supplemental Balance Sheet Disclosures [Line Items] Supplemental Balance Sheet Disclosures [Line Items] Granted, weighted average grant date fair value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Related and Nonrelated Parties [Axis] Related and Nonrelated Parties [Axis] Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Member Notes Member Notes [Member] Member Notes Schedule of Intangible Assets, Net Schedule of Finite-Lived Intangible Assets [Table Text Block] Restatement Determination Date: Restatement Determination Date [Axis] Forfeiture of Class X Umbrella Units and corresponding cancellation of Class B common stock Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Non-PEO NEO Non-PEO NEO [Member] Outstanding amount Letters of Credit Outstanding, Amount Balance Balance Members' Equity Holdover Note Holdover Note [Member] Holdover Note Schedule of Prepaid Expenses and Other Current Assets Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block] Interest expense Interest Expense, Debt Sale of Stock [Axis] Sale of Stock [Axis] Name Trading Arrangement, Individual Name Allowance for credit loss Beginning balance Ending balance Financing Receivable, Allowance for Credit Loss All Award Types Award Type 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