Business Acquisition [Axis] Business Acquisition [Axis] Due within one year Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Foreign Current Foreign Tax Expense (Benefit) Total lease payments Lessee, Operating Lease, Liability, to be Paid Foreign Currency and Transaction Gains and Losses Foreign Currency Transactions and Translations Policy [Policy Text Block] NET INCOME INCLUDING NON-CONTROLLING INTERESTS Net income including non-controlling interests Net Income (Loss), Including Portion Attributable to Noncontrolling Interest APAC Asia Pacific and Japan [Member] Asia Pacific and Japan [Member] Leasehold improvements Leaseholds and Leasehold Improvements [Member] DEFERRED TAX ASSETS Deferred Income Tax Assets, Net Total debt Long-Term Debt, Gross Entity Address, Postal Zip Code Entity Address, Postal Zip Code Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Deferred: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Payments of debt assumed in connection with business combination Repayments of Assumed Debt Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Business Combinations Business Combinations Policy [Policy Text Block] Debt Instrument [Axis] Debt Instrument [Axis] Earnings Per Share [Line Items] Earnings Per Share [Line Items] Earnings Per Share [Line Items] Total property and equipment Property, Plant and Equipment, Gross Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Prepaid expenses and other current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets Remaining terms (less than for minimum) Operating Lease, Remaining Lease Term Operating Lease, Remaining Lease Term Inventory, Net [Abstract] Inventory, Net [Abstract] Changes in operating assets and liabilities, net of impact of business combinations: Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract] Financial Instruments and Fair Value Fair Value of Financial Instruments, Policy [Policy Text Block] Number of primary stock incentive plans Share-based Compensation Arrangement by Share-based Payment Award, Number of Primary Stock Incentive Plans Share-based Compensation Arrangement by Share-based Payment Award, Number of Primary Stock Incentive Plans Fair Value Measurement [Domain] Fair Value Measurement [Domain] Financial Instruments [Domain] Financial Instruments [Domain] Purchases of marketable equity securities Payments for (Proceeds from) Other Investing Activities Statistical Measurement [Domain] Statistical Measurement [Domain] Depreciation Depreciation Exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Net deferred tax assets Deferred Tax Assets, Net Short-term investments Short Term Investments, Line Item [Member] Short Term Investments, Line Item [Member] Stated interest rate Coupon Rate Debt Instrument, Interest Rate, Stated Percentage Weighted average discount rate – operating leases Operating Lease, Weighted Average Discount Rate, Percent Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Gross decreases for tax positions related to expiration of statute of limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Additional paid-in capital Additional Paid in Capital, Common Stock Summary of Investments Schedule of Amortized Costs, Unrealized Gains and Losses, and Fair Value of Available For Sale Securities [Table Text Block] Schedule of Amortized Costs, Unrealized Gains and Losses, and Fair Value of Available For Sale Securities [Table Text Block] Federal [Member] Domestic Tax Authority [Member] Other Other Noncash Income (Expense) State Current State and Local Tax Expense (Benefit) Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] NET INCOME ATTRIBUTABLE TO FORTINET, INC. Net Income (Loss) Attributable to Parent Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Anti-dilutive securities (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Subsequent Event Type [Axis] Subsequent Event Type [Axis] Foreign withholding taxes Effective Income Tax Rate Reconciliation, Foreign Withholding Taxes, Amount Effective Income Tax Rate Reconciliation, Foreign Withholding Taxes, Amount Share Repurchase Program [Domain] Share Repurchase Program [Domain] Thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Five Schedule of Range of Options Share-Based Payment Arrangement, Option, Exercise Price Range [Table Text Block] Equity Component [Domain] Equity Component [Domain] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Total Assets, Fair Value Disclosure Assets, Fair Value Disclosure Options Outstanding, Number Outstanding (in shares) Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding Gross increases for tax positions related to the current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Investment, Name [Domain] Investment, Name [Domain] LEASES Lessee, Operating Leases [Text Block] Options Outstanding, Weighted Average Exercise Price (in dollars per share) Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price Lease not yet commenced, approximate term Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract Cash, Cash Equivalents and Available-for-sale Investments Cash and Cash Equivalents and Available-for-Sale Investments [Policy Text Block] Cash and Cash Equivalents and Available-for-Sale Investments [Policy Text Block] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Plan Name [Axis] Plan Name [Axis] Fair Value Fair Value Investments, Fair Value Disclosure Debt Securities, Available-for-Sale Backlog Backlog [Member] Backlog Research and Development Costs and Software Development Costs Research, Development, and Computer Software, Policy [Policy Text Block] Restricted Stock Units and Options Restricted Stock Units and Options [Member] Restricted Stock Units and Options Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION: Supplemental Cash Flow Information [Abstract] Forfeited (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Number of operating segments (in operating segments) Number of Operating Segments Plan Name [Domain] Plan Name [Domain] DEFERRED CONTRACT COSTS Capitalized Contract Cost, Net Schedule of Estimated Useful Lives of Property and Equipment - net Schedule of Estimated Useful Lives of Property, Plant and Equipment [Table Text Block] Schedule of Estimated Useful Lives of Property, Plant and Equipment [Table Text Block] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Entity Address, State or Province Entity Address, State or Province Level 1 Fair Value, Inputs, Level 1 [Member] Options outstanding, Weighted average remaining contractual life (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Award Type [Axis] Award Type [Axis] Minimum stock ownership percent triggering early award expiration Share-based Compensation Arrangement by Share-based Payment Award, Minimum Stock Ownership Percent Triggering Early Award Expiration Share-based Compensation Arrangement by Share-based Payment Award, Minimum Stock Ownership Percent Triggering Early Award Expiration Gross decreases for tax positions related to prior year audit settlements Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Basic shares: Weighted Average Number of Shares Outstanding, Basic [Abstract] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Operating lease liabilities – current Operating Lease, Liability, Current Deferred Contract Costs Commissions Expense, Policy [Policy Text Block] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Accounts receivable—net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Property and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Document Annual Report Document Annual Report Short-term investments Other Short-Term Investments LONG-TERM DEBT Total long-term debt Long-Term Debt, Excluding Current Maturities Certificates of deposit and term deposits Certificates of Deposit [Member] Total liabilities Liabilities Weighted average remaining lease term in years – operating leases Operating Lease, Weighted Average Remaining Lease Term Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share Repurchase Program [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Geographical [Axis] Statement, Geographical [Axis] Geographical [Axis] CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Equity interests acquired Business Acquisition, Percentage of Voting Interests Acquired Additional shares authorized Stock Repurchase Program, Authorized Amount, Approved Increase Stock Repurchase Program, Authorized Amount, Approved Increase Cash Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Other liabilities Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Schedule of Property, Plant and Equipment - Net Property, Plant and Equipment [Table Text Block] $39.68-$68.70 Price Range Four [Member] Price Range Four [Member] Deferred Revenue Revenue from Contract with Customer [Policy Text Block] Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Document Type Document Type Weighted- Average Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Property and equipment, useful life Property, Plant and Equipment, Useful Life Gain on intellectual property matter Gain (Loss) From Mutual Covenant-Not-To-Sue Agreement, Right To Use Existing Intellectual Property Gain (Loss) From Mutual Covenant-Not-To-Sue Agreement, Right To Use Existing Intellectual Property Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Revenue from External Customer [Line Items] Revenue from External Customer [Line Items] Property, Plant and Equipment, Net, by Type [Abstract] Property, Plant and Equipment, Net, by Type [Abstract] Estimate for sales return reserve Contract with Customer, Refund Liability, Current Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Software Products [Member] Software, Product Warranty [Member] Software, Product Warranty Balance, beginning (in dollars per share) Balance, ending (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Debt Debt Disclosure [Text Block] DEFINED CONTRIBUTION PLANS Compensation and Employee Benefit Plans [Text Block] Product and Service [Domain] Product and Service [Domain] General business credit carryforward Deferred Tax Assets, Tax Credit Carryforwards, General Business Entity Shell Company Entity Shell Company Total deferred Deferred Income Tax Expense (Benefit) Concentration Risk Concentration Risk [Policy Text Block] Concentration Risk [Policy Text Block] Accrued liabilities Increase (Decrease) in Accrued Liabilities Gross decreases for tax positions related to prior year Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Axis] Exercise Price Range [Axis] 2023 Lessee, Operating Lease, Liability, to be Paid, Year One Evaluation units Evaluation Units [Member] Evaluation units [Member] Developed technology Developed Technology Rights [Member] Schedule of Available-for-sale Securities, Major Types of Debt and Equity Securities [Axis] Financial Instrument [Axis] Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] FINANCIAL INSTRUMENTS AND FAIR VALUE Financial Instruments Disclosure [Text Block] Subsequent Event Subsequent Event [Member] Revenue Benchmark Revenue Benchmark [Member] Document Period End Date Document Period End Date Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] Share-Based Payment Arrangement, Option, Exercise Price Range [Line Items] Schedule of Warranties [Table] Schedule of Warranties [Table] Schedule of Warranties [Table] Due within one to three years Available-for-sale Securities, Debt Maturities, after One Year, Fair Value This item represents the fair value of debt securities which are expected to mature after one year from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities. TOTAL ASSETS Assets Foreign tax credit Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount Debt Disclosure [Abstract] Net income per share attributable to Fortinet, Inc. (Note $9): Earnings Per Share [Abstract] Accounts receivable Accounts Receivable [Policy Text Block] Income Statement Location [Axis] Income Statement Location [Axis] Change in unrealized gains (losses) on investments OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax Antidilutive Securities Excluded from Computation of Earnings Per Share, by Antidilutive Securities [Axis] Antidilutive Securities [Axis] Marketable equity securities Equity Securities, FV-NI, Current Balance, beginning of period (in shares) Balance, end of period (in shares) Shares, Issued Accrued liabilities Accrued Liabilities, Current 2009 Equity Incentive Plan (Amended Plan) Stock Plan, 2009 [Member] Stock Plan, 2009 [Member] Panopta Holdings LLC Panopta Holdings LLC [Member] Panopta Holdings LLC Exercised (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price 2027 Lessee, Operating Lease, Liability, to be Paid, Year Five Fair Value Finite-Lived Intangible Assets Acquired Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Estimated fair value of outstanding debt Long-Term Debt, Fair Value Accounting Policies [Abstract] Accounting Policies [Abstract] LONG-TERM INVESTMENTS Long-Term Investments Stock repurchase program, authorized amount Stock Repurchase Program, Authorized Amount Interest expense Interest Expense, Debt Accrued payroll and compensation Employee-related Liabilities, Current Variable lease expense Variable Lease, Cost Issuance of common stock in connection with equity incentive plans - net of tax withholding (in shares) Stock Issued During Period, Shares, Equity Incentive Plans Stock Issued During Period, Shares, Equity Incentive Plans EQUITY (DEFICIT): Stockholders' Equity Attributable to Parent [Abstract] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current NET INCOME PER SHARE Earnings Per Share [Text Block] Customer [Axis] Customer [Axis] Municipal bonds Municipal Bonds [Member] Comprehensive income including non-controlling interests Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Schedule of Components of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Fair value of options vested Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested in Period, Fair Value Award Type [Domain] Award Type [Domain] Compensation cost not yet recognized period of recognition Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Total, Unrealized Losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Options exercisable, Weighted average remaining contractual life (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Schedule of Finite-Lived Intangible Assets by Major Class Schedule of Finite-Lived Intangible Assets [Table Text Block] Cash consideration Payments to Acquire Businesses, Gross Computer equipment and software Computer Equipment [Member] Schedule of Shares Reserved for Future Issuance Schedule of Shares Reserved for Future Issuance [Table Text Block] Schedule of Shares Reserved for Future Issuance [Table Text Block] Purchases of investments Payments to Acquire Other Investments Total gross profit Gross Profit Entity Registrant Name Entity Registrant Name Goodwill Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Subsequent Event Subsequent Events [Text Block] Inventory Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory Dividend rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate Exercise Price, maximum (in dollars per share) Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit Foreign currency translation adjustments Goodwill, Foreign Currency Translation Gain (Loss) Customer relationships Customer Relationships [Member] Entity Address, City or Town Entity Address, City or Town Leases [Abstract] Leases [Abstract] OPERATING EXPENSES: Operating Expenses [Abstract] Total equity (deficit) Balance, beginning of period Balance, end of period Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Net decrease of gross unrecognized tax benefits Unrecognized Tax Benefits, Period Increase (Decrease) Net operating loss carryforward Deferred Tax Assets, Operating Loss Carryforwards Long-term investments, minimum original maturity Investments, Classification as Long-term, Minimum Maturity Investments, Classification as Long-term, Minimum Maturity Minimum Minimum [Member] Schedule of Share-based Compensation, Stock Options, Activity, Additional Information Schedule of Share-based Compensation, Stock Options, Activity, Additional Information [Table Text Block] Schedule of Share-based Compensation, Stock Options, Activity, Additional Information Non-controlling interests Stockholders' Equity Attributable to Noncontrolling Interest Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Entity Emerging Growth Company Entity Emerging Growth Company Common Stock, par value (dollars per share) Common Stock, Par or Stated Value Per Share Raw materials Inventory, Raw Materials, Net of Reserves Other intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Stock-based compensation expense Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-Based Payment Arrangement, Amount Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Auditor Name Auditor Name Investment, Name [Axis] Investment, Name [Axis] Net operating loss carryforwards Operating Loss Carryforwards Trading Symbol Trading Symbol Entity File Number Entity File Number 2026 Finite-Lived Intangible Asset, Expected Amortization, Year Four Options Outstanding, Weighted Average Remaining Contractual Life (in years) Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term Research and development Research and Development Expense Canada CANADA Gross increases for tax positions related to the prior year Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Deferred revenue Deferred Revenue, Current Foreign Deferred Foreign Income Tax Expense (Benefit) Deferred Compensation Arrangement with Individual, Share-based Payments, by Title of Individual [Axis] Title of Individual [Axis] Linksys Linksys [Member] Linksys Granted (shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period RSUs Restricted Stock Units (RSUs) [Member] Cost of service revenue Cost of Services [Member] Cost of Services [Member] Concentration Risk by Benchmark [Axis] Concentration Risk Benchmark [Axis] Matching contributions to the RRSP and 401(k) Plans Defined Contribution Plan, Employer Matching Contribution, Amount Defined Contribution Plan, Employer Matching Contribution, Amount Research and development credit Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount Options vested and expected to vest, Outstanding (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Use of Estimates Use of Estimates, Policy [Policy Text Block] BUSINESS COMBINATIONS Business Combination Disclosure [Text Block] Stock Options and Restricted Stock Units, Outstanding Stock Options and Restricted Stock Units, Outstanding [Member] Stock Options and Restricted Stock Units, Outstanding [Member] Accounts payable Increase (Decrease) in Accounts Payable Purchase price Net purchase consideration Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Concentration (percent) Concentration Risk, Percentage Subsequent Events [Abstract] Subsequent Events [Abstract] Liability incurred in connection with business combination Business Combination, Consideration Transferred, Liabilities Incurred Pro forma net income attributable to Fortinet, Inc. Business Acquisition, Pro Forma Net Income (Loss) INVESTMENTS IN PRIVATELY HELD COMPANIES Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] INTEREST INCOME Investment Income, Net INCOME TAXES Income Tax Disclosure [Text Block] State Deferred State and Local Income Tax Expense (Benefit) Finished goods Inventory, Finished Goods, Net of Reserves California [Member] State Jurisdiction, California [Member] State Jurisdiction, California [Member] 12 Months or Greater, Fair Value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Cash paid for amounts included in the measurement of lease liabilities Cash Flow, Lessee [Abstract] Cash Flow, Lessee [Abstract] Amortization expense Amortization of Intangible Assets Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activities Schedule of Changes in Carrying Value of Goodwill Schedule of Goodwill [Table Text Block] Basic (in dollars per share) Earnings Per Share, Basic Commissions Expense [Table] Commissions Expense [Table] Commissions Expense [Table] Hardware Products [Member] Hardware, Product Warranty [Member] Hardware, Product Warranty [Member] 2025 Lessee, Operating Lease, Liability, to be Paid, Year Three Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Accounts payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Inventory Inventory, Policy [Policy Text Block] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Sales and marketing Selling and Marketing Expense Total Fortinet, Inc. stockholders’ equity (deficit) Stockholders' Equity Attributable to Parent Tax credit carryforwards Tax Credit Carryforward, Amount Finance lease liabilities arising from obtaining right-of-use assets Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Forfeited (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Entity Interactive Data Current Entity Interactive Data Current Amortization of deferred contract costs Capitalized Contract Cost, Amortization Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Schedule of Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Foreign-Derived Intangible Income Effective Income Tax Rate Reconciliation, Tax Cuts And Jobs Act, Deduction, Foreign-Derived Intangible Income, Amount Effective Income Tax Rate Reconciliation, Tax Cuts And Jobs Act, Deduction, Foreign-Derived Intangible Income, Amount 2025 Finite-Lived Intangible Asset, Expected Amortization, Year Three Sales of investments Proceeds from Sale of Debt Securities, Available-for-Sale Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Retained Earnings (Accumulated Deficit) Retained Earnings [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Total lease expense Lease, Cost Common Stock Common Stock [Member] Other Americas Other Americas [Member] Other Americas [Member] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Number of reportable segments (in reportable segments) Number of Reportable Segments Components of Lease Expense and Supplemental Cash Flow Information Lease, Cost [Table Text Block] Repurchase and retirement of common stock Payments for Repurchase of Common Stock Deferred contract costs Increase (Decrease) in Deferred Charges Remaining shares available for grant under the plans (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Supplemental Balance Sheet Information Assets And Liabilities, Lessee [Table Text Block] Assets And Liabilities, Lessee [Table Text Block] Revenue Recognition Revenue [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Marketable Equity Securities Marketable Securities, Policy [Policy Text Block] Statement [Table] Statement [Table] Vested (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Effective Interest Rate Debt Instrument, Interest Rate, Effective Percentage Loss from equity method investment Equity Method Investment, Realized Gain (Loss) on Disposal Renewal terms (up to) Lessee, Operating Lease, Renewal Term Commercial paper Commercial Paper, Not Included with Cash and Cash Equivalents [Member] Schedule of Share-based Compensation, Shares Withheld for Taxes Schedule of Share-based Compensation, Shares Withheld for Taxes [Table Text Block] Schedule of Share-based Compensation, Shares Withheld for Taxes [Table Text Block] Schedule of Earnings Per Share [Table] Schedule of Earnings Per Share [Table] Schedule of Earnings Per Share [Table] TOTAL ASSETS Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Furniture and fixtures Furniture and Fixtures [Member] CURRENT ASSETS: Assets, Current [Abstract] Operating lease liabilities – non-current Operating Lease, Liability, Noncurrent Statistical Measurement [Axis] Statistical Measurement [Axis] Schedule of Employee Service Share based Compensation Allocation of Recognized Period Costs by Award Type Schedule of Employee Service Share based Compensation Allocation of Recognized Period Costs by Award Type [Table Text Block] Schedule of Employee Service Share based Compensation Allocation of Recognized Period Costs by Award Type [Table Text Block] Marketable equity securities, realized loss Equity Securities, FV-NI, Realized Gain (Loss) Revenue from external customers by geographic region Revenue from External Customers by Geographic Areas [Table Text Block] Accumulated deficit Retained Earnings (Accumulated Deficit) Cost of product revenue Cost of Goods Sold [Member] Cost of Goods Sold [Member] Accounts receivable—Net of allowance for credit losses of $3.6 million and $2.4 million at December 31, 2022 and 2021, respectively Accounts Receivable, after Allowance for Credit Loss, Current Schedule of Finite-Lived Intangible Assets by Major Class [Table] Schedule of Finite-Lived Intangible Assets [Table] U.S. government and agency securities US Treasury and Government [Member] Equity Components [Axis] Equity Components [Axis] Recurring Fair Value, Recurring [Member] Options exercisable, Weighted average exercise price (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest [Abstract] Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest [Abstract] Business Acquisition, Pro Forma Information Business Acquisition, Pro Forma Information [Table Text Block] Less Than 12 Months, Fair Value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Document Fiscal Year Focus Document Fiscal Year Focus Schedule of Acquired Finite-Lived Intangible Assets by Major Class Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block] CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income per share attributable to Fortinet, Inc. (Note $9): Earnings Per Share, Basic and Diluted EPS [Abstract] Earnings Per Share, Basic and Diluted EPS Statement [Line Items] Statement [Line Items] Valuation allowance on deferred tax assets related to equity method investment Valuation Allowance, Deferred Tax Assets Related to Equity Method Investment, Increase (Decrease), Amount Valuation Allowance, Deferred Tax Assets Related to Equity Method Investment, Increase (Decrease), Amount Balance, beginning (shares) Balance, ending (shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Gross Finite-Lived Intangible Assets, Gross Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Total current Current Income Tax Expense (Benefit) Operating lease ROU assets – non-current Operating Lease, Right-of-Use Asset Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Product Product [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Segment managers responsible for operations (in segment managers) Number of Segment Managers Responsible for Operations Number of Segment Managers Responsible for Operations Impairment of Long-Lived Assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Auditor Firm ID Auditor Firm ID Deferred tax liabilities: Deferred Tax Liabilities, Gross [Abstract] Options vested and expected to vest, Weighted average exercise price (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Purchases of property and equipment Payments to Acquire Productive Assets Individual Owning Less Than 10 Percent of Stock Individual Owning Less Than 10 Percent of Stock [Member] Individual Owning Less Than 10 Percent of Stock [Member] Document Transition Report Document Transition Report Local Phone Number Local Phone Number Basis of Presentation and Preparation Presentation and Preparation of Consolidated Financial Statements [Policy Text Block] Presentation and Preparation of Consolidated Financial Statements [Policy Text Block] Schedule of Share-based Compensation, Stock Options, Activity Share-Based Payment Arrangement, Option, Activity [Table Text Block] OPERATING INCOME Operating Income (Loss) Inventory Increase (Decrease) in Inventories Recently Adopted and Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Stock-based compensation expense Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-Based Compensation Cost Investments in equity securities of privately-held companies Equity Securities without Readily Determinable 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by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Distributor B Distributor B [Member] Distributor B City Area Code City Area Code Options Exercisable, Weighted Average Exercise Price (in dollars per share) Share-Based Payment Arrangement, Option, Exercise Price Range, Exercisable, Weighted Average Exercise Price General and administrative General and Administrative Expense ASSETS Assets [Abstract] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Retirement Benefits [Abstract] Retirement Benefits [Abstract] Deferred Taxes [Line Items] Deferred Taxes [Line Items] Deferred Taxes [Line Items] Total Inventory purchase commitments Purchase Obligation Schedule of Unrealized Loss on Investments Schedule of Unrealized Loss on Investments [Table Text Block] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Tax at federal statutory tax rate Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Advertising Expense Advertising Cost [Policy Text Block] Maturities of investments Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Less: comprehensive income (loss) attributable to non-controlling interests Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest Change in foreign currency translation Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax Distributor A Distributor A [Member] Distributor A NON-CASH INVESTING AND FINANCING ACTIVITIES: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Stock-based compensation Share-Based Payment Arrangement, Noncash Expense Deferred contract costs Deferred Tax Liabilities, Deferred Expense Investment in privately held company Purchase of investment in privately held company Payments to Acquire Equity Method Investments Weighted-average fair value per share granted Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Income Tax Benefit from Stock Option Plans Income Tax Benefit from Stock Option Plans [Table Text Block] Income Tax Benefit from Stock Option Plans [Table Text Block] Technical Support and Other [Member] Technical Support and Other [Member] Technical Support and Other [Member] OTHER LIABILITIES Other Liabilities, Noncurrent LOSS FROM EQUITY METHOD INVESTMENT Loss from equity method investment Income (Loss) from Equity Method Investments Gross decreases for tax positions related to the current year Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions Available-for-sale Securities, Debt Maturities, Fair Value [Abstract] Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract] Cash payments to purchase real estate Payments to Acquire Property, Plant, and Equipment Research and development Research and Development Expense [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] 2023 Finite-Lived Intangible Asset, Expected Amortization, Year One Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Operating lease liabilities arising from obtaining right-of-use assets Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Customer [Domain] Customer [Domain]