Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Earnings Per Share [Abstract] Numerator: Numerator [Abstract] Numerator [Abstract] Net income Net Income (Loss) Attributable to Parent Denominator: Denominator [Abstract] Denominator [Abstract] Basic (shares) Weighted Average Number of Shares Outstanding, Basic Common stock options (shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Restricted stock units (shares) Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants Diluted (shares) Weighted Average Number of Shares Outstanding, Diluted Basic (USD per share) Earnings Per Share, Basic Diluted (USD per share) Earnings Per Share, Diluted Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Stock Options Employee Stock Option [Member] Restricted Stock Units Restricted Stock Units (RSUs) [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Antidilutive Securities [Abstract] Antidilutive Securities [Abstract] Antidilutive securities (shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Revenue from Contract with Customer [Abstract] Commission asset balances Contract With Customer, Commission Asset Balances [Table Text Block] Contract With Customer, Commission Asset Balances [Table Text Block] Contract liabilities Contract with Customer, Asset and Liability [Table Text Block] Accounts receivable, net Contract With Customer, Accounts Receivable Disclosure [Table Text Block] Contract With Customer, Accounts Receivable Disclosure [Table Text Block] Expected revenue from contracts Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Revenue by sales channel Disaggregation of Revenue [Table Text Block] Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] United States UNITED STATES Other Other Geographic Areas [Member] Other Geographic Areas [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Number of operating segments (in segment) Number of Operating Segments Property and equipment, net Property, Plant and Equipment, Net Commitments and Contingencies Disclosure [Abstract] Schedule of Future Minimum Lease Payments for Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Subsequent Events [Abstract] Subsequent Event Subsequent Events [Text Block] Fair Value Disclosures [Abstract] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Unrealized Gain (Loss) on Investments Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] AOCI Attributable to Parent, Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Beginning balance Stockholders' Equity Attributable to Parent Change in net unrealized loss on available-for-sale marketable securities, net of tax Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Amounts reclassified for net realized gain included in net income, net of tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Other comprehensive income (loss), net Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Ending balance Statement of Financial Position [Abstract] Assets Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Short-term marketable securities Marketable Securities, Current Accounts receivable, net of allowance of $764 and $816 as of September 30, 2018 and December 31, 2017, respectively Accounts Receivable, Net, Current Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Long-term marketable securities Marketable Securities, Noncurrent Deferred tax assets, net Deferred Tax Assets, Net, Noncurrent Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Long-term investment Long-term Investments Goodwill Goodwill Restricted cash Restricted Cash and Cash Equivalents, Noncurrent Other noncurrent assets Other Assets, Noncurrent Total assets Assets Liabilities and Stockholders’ Equity Liabilities and Equity [Abstract] Current liabilities : Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued liabilities Accrued Liabilities, Current Deferred revenues, current Deferred Revenue, Current Total current liabilities Liabilities, Current Deferred revenues, noncurrent Deferred Revenue, Noncurrent Other noncurrent liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies (Note 7) Commitments and Contingencies Stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, $0.001 par value; 20,000,000 shares authorized, no shares issued and outstanding at September 30, 2018 and December 31, 2017 Preferred Stock, Value, Issued Common stock, $0.001 par value; 1,000,000,000 shares authorized; 39,341,476 and 38,598,117 shares issued and outstanding at September 30, 2018 and December 31, 2017 Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Retained earnings Retained Earnings (Accumulated Deficit) Total stockholders’ equity Total liabilities and stockholders’ equity Liabilities and Equity Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] 1Mobility 1Mobility [Member] 1Mobility [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Total purchase price Business Combination, Consideration Transferred Deferred consideration Payments To Acquire Businesses Gross, Payable Subject To Future Terms Of Purchase Agreement Payments To Acquire Businesses Gross, Payable Subject To Future Terms Of Purchase Agreement Technology-based intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Estimated useful life of technology-based intangible assets Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Business Combination Business Combination Disclosure [Text Block] Equity [Abstract] Share repurchase program, authorized amount Stock Repurchase Program, Authorized Amount Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Class of Stock [Line Items] Class of Stock [Line Items] Share repurchased, additional authorized amount Stock Repurchase Program, Additional Authorized Amount Stock Repurchase Program, Additional Authorized Amount Shares repurchased during period (in shares) Treasury Stock, Shares, Acquired Shares repurchased during period, value Treasury Stock, Value, Acquired, Cost Method Remaining authorized amount Stock Repurchase Program, Remaining Authorized Repurchase Amount Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Goodwill and Intangible Assets [Table] Schedule of Goodwill and Intangible Assets [Table] Schedule of Goodwill and Intangible Assets [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Developed technology Developed Technology Rights [Member] Patent licenses Patents [Member] Schedule of Goodwill and Intangible Assets [Line Items] Schedule of Goodwill and Intangible Assets [Line Items] [Line Items] for Schedule of Goodwill and Intangible Assets [Table] Weighted Average Life (Years) Finite-Lived Intangible Asset, Useful Life Weighted Average Remaining Life (Years) Finite-Lived Intangible Assets, Remaining Amortization Period Cost Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Net Book Value Finite-Lived Intangible Assets, Net Intangible assets not subject to amortization Indefinite-Lived Intangible Assets (Excluding Goodwill) Total intangible assets, net Amortization of intangible assets Amortization of Intangible Assets Accounting Policies [Abstract] Description Of Business Description Of Business Policy [Policy Text Block] Description Of Business Policy [Policy Text Block] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Recently adopted Accounting Pronouncements and Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Fair Value of Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Property, Plant and Equipment [Abstract] Schedule of Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Computer equipment Computer Equipment [Member] Computer software Computer Software, Intangible Asset [Member] Furniture, fixtures and equipment Furniture and Fixtures [Member] Assets under capital lease Assets Held under Capital Leases [Member] Scanner appliances Scanner appliances [Member] Scanner appliances [Member] Scanner appliances and other computer equipment subject to subscription Scanner appliances and other computer equipment subject to subscription [Member] Scanner appliances and other computer equipment subject to subscription [Member] Scanner appliances and other computer equipment not placed in service Scanner Appliances and Other Computer Equipment Not Placed in Service [Member] Scanner Appliances and Other Computer Equipment Not Placed in Service [Member] Leasehold improvements Leasehold Improvements [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Property and equipment Property, Plant and Equipment, Gross Less: accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property and equipment, net Depreciation and amortization expense Depreciation, Depletion And Amortization, Excluding Intangible Asset Amortization Depreciation, Depletion And Amortization, Excluding Intangible Asset Amortization Capital leases, accumulated depreciation Accumulated Depreciation, Capital Leases Accumulated Depreciation, Capital Leases Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization expense Depreciation, Depletion and Amortization Bad debt expense Provision for Doubtful Accounts Loss on disposal of property and equipment Gain (Loss) on Disposition of Property Plant Equipment Stock-based compensation Share-based Compensation Amortization of premiums and accretion of discounts on marketable securities Accretion (Amortization) of Discounts and Premiums, Investments Deferred income taxes Deferred Income Tax Expense (Benefit) Excess tax benefits from stock-based compensation Excess Tax Benefit from Share-based Compensation, Operating Activities Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Accounts payable Increase (Decrease) in Accounts Payable Accrued liabilities Increase (Decrease) in Accrued Liabilities Deferred revenues Increase (Decrease) in Deferred Revenue Other non-current liabilities Increase (Decrease) in Other Noncurrent Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Purchases of marketable securities Payments to Acquire Available-for-sale Securities Sales and maturities of marketable securities Proceeds from Sale and Maturity of Available-for-sale Securities Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Business acquisition Payments to Acquire Businesses, Gross Purchase of privately-held investment Payments to Acquire Investments Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from exercise of stock options Proceeds from Stock Options Exercised Payments for taxes related to net share settlement of equity awards Payments Related to Tax Withholding for Share-based Compensation Principal payments under capital lease obligations Repayments of Long-term Capital Lease Obligations Repurchase of common stock Payments for Repurchase of Common Stock Net cash (used in) provided by financing activities Net Cash Provided by (Used in) Financing Activities Effect of Exchange Rate on Cash and Cash Equivalents, Continuing Operations Effect of Exchange Rate on Cash and Cash Equivalents, Continuing Operations Net increase in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash, cash equivalents and restricted cash at beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, cash equivalents and restricted cash at end of period Supplemental disclosures of cash flow information: Supplemental Cash Flow Information [Abstract] Cash paid for interest expense Interest Paid Cash paid for income taxes, net of refunds Income Taxes Paid, Net Purchases of property and equipment recorded in accounts payable and accrued liabilities Capital Expenditures Incurred but Not yet Paid Purchase of assets under capital lease Noncash or Part Noncash Acquisition, Fixed Assets Acquired Not yet received tenant allowance recorded in other assets, accrued liabilities and other non-current liabilities Not Yet Received Tenant Allowance Not Yet Received Tenant Allowance Segment Information and Information about Geographic Area Segment Reporting Disclosure [Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2012 Equity Incentive Plan 2012 Equity Incentive Plan [Member] 2012 Equity Incentive Plan [Member] 2000 Equity Incentive Plan 2000 Equity Incentive Plan [Member] 2000 Equity Incentive Plan [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Number of shares authorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Number of shares available for grant Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Derivative, by Nature [Axis] Derivative Instrument [Axis] Derivative, Name [Domain] Derivative Contract [Domain] Forward Contracts Forward Contracts [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Net (loss) gain from forward contracts Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Other foreign currency transactions (loss) gain Foreign Currency Transaction Gain (Loss), before Tax Total foreign exchange loss, net Foreign Currency Transaction Gain (Loss) Including Derivatives, Before Tax Foreign Currency Transaction Gain (Loss) Including Derivatives, Before Tax Subsequent Event [Table] Subsequent Event [Table] Layered Insights Layered Insights [Member] Layered Insights [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Cash payable in future subject to terms and conditions of purchase agreement Additional cash payments Business Combination, Additional Cash Payments Business Combination, Additional Cash Payments Potential future payments to acquired company Potential Future Payments to Acquired Company Future Payments to Acquired Company Schedule of Cash and Cash Equivalents, Available-for-sale Securities Reconciliation Available-for-sale Securities [Table Text Block] Schedule of changes to accumulated other comprehensive income Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Assets Measured on Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Schedule of Available-for-Sale Securities by Contractual Maturity Investments Classified by Contractual Maturity Date [Table Text Block] Summary of Gains (Losses) Recognized From Forward Contracts and Other Foreign Currency Transactions Derivative Instruments, Gain (Loss) [Table Text Block] Stock-based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Commercial paper Commercial Paper [Member] US Treasury Bill Securities [Member] US Treasury Bill Securities [Member] US government agencies US Government Agencies Debt Securities [Member] Corporate bonds Corporate Bond Securities [Member] Asset backed securities Asset-backed Securities [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Basis Fair Value, Measurements, Recurring [Member] 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] Assets, Fair Value Disclosure [Abstract] Assets, Fair Value Disclosure [Abstract] Available-for-sale securities, fair value Available-for-sale Securities Goodwill and Intangible Assets, Net Goodwill and Intangible Assets Disclosure [Text Block] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Employee stock-based compensation Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Stock option activity Share-based Compensation, Stock Options, Activity [Table Text Block] Restricted stock units activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Outstanding RSUs and RSAs Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Beginning balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Released (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Canceled (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Ending balance (in shares) Outstanding and expected to vest (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Vested And Expected To Vest, Outstanding, Number Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Vested And Expected To Vest, Outstanding, Number Weighted Average Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Beginning balance (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted (usd 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 Released (usd 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 Canceled (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Ending balance (usd per share) Outstanding and expected to vest (usd per share) Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Vested And Expected To Vest, Outstanding, Weighted Average Exercise Price Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Vested And Expected To Vest, Outstanding, Weighted Average Exercise Price (Benefit from) provision for income taxes Income Tax Expense (Benefit) Effective tax rate Effective Income Tax Rate Reconciliation, Percent Unrecognized Tax Benefits Unrecognized Tax Benefits Unrecognized Tax Benefits that Would Impact Effective Tax Rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Net Income Per Share Earnings Per Share [Text Block] Operating Leases Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2018 (remaining three months) Operating Leases, Future Minimum Payments, Remainder of Fiscal Year 2019 Operating Leases, Future Minimum Payments, Due in Two Years 2020 Operating Leases, Future Minimum Payments, Due in Three Years 2021 Operating Leases, Future Minimum Payments, Due in Four Years 2022 Operating Leases, Future Minimum Payments, Due in Five Years 2023 and thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total minimum lease payments Operating Leases, Future Minimum Payments Due Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2018 (remaining three months) Capital Leases, Future Minimum Payments, Remainder of Fiscal Year 2019 Capital Leases, Future Minimum Payments Due in Two Years 2020 Capital Leases, Future Minimum Payments Due in Three Years 2021 Capital Leases, Future Minimum Payments Due in Four Years 2022 Capital Leases, Future Minimum Payments Due in Five Years 2023 and thereafter Capital Leases, Future Minimum Payments Due Thereafter Total minimum lease payments Capital Leases, Future Minimum Payments Due Less: amount representing interest Capital Leases, Future Minimum Payments, Interest Included in Payments Present value of minimum payments Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments Less: current portion Capital Leases, Future Minimum Payments Due, Next Twelve Months Capital lease obligations, noncurrent Capital Leases, Future Minimum Payments, Noncurrent Capital Leases, Future Minimum Payments, Noncurrent Revenues be geographic area Revenues and property and equipment, net, by geographic area Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block] Property and equipment, net Property, Plant and Equipment [Table Text Block] Revenue from Contracts with Customers Revenue from Contract with Customer [Text Block] ASC 606 receivables Contract with Customer, Asset, Net Operating lease receivables Operating Leases, Future Minimum Payments Receivable, Current Allowance for doubtful accounts receivable Allowance for Doubtful Accounts Receivable Total accounts receivable, net Property and Equipment, Net Property, Plant and Equipment Disclosure [Text Block] Statement of Comprehensive Income [Abstract] Available-for-sale marketable securities: Available-for-sale Securities [Abstract] Change in net unrealized (loss) gain, net of tax Reclassification adjustment for net realized gain included in net income, net of tax Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs, by Report Line [Axis] Income Statement Location [Axis] Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Report Line [Domain] Income Statement Location [Domain] Cost of revenues Cost of Sales [Member] Research and development Research and Development Expense [Member] Sales and marketing Selling and Marketing Expense [Member] General and administrative General and Administrative Expense [Member] Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Total employee stock-based compensation Allocated Share-based Compensation Expense Unrecognized employee compensation cost Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Unrecognized employee compensation cost, period for recognition Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Commission asset, current Commission Asset, Current Commission Asset, Current Commission asset, noncurrent Commission Asset, Non-current Commission Asset, Non-current Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2014-09 Accounting Standards Update 2014-09 [Member] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Domain] Initial Application Period Cumulative Effect Transition [Domain] Difference between Revenue Guidance in Effect before and after Topic 606 Difference between Revenue Guidance in Effect before and after Topic 606 [Member] Reclassification Error Corrections and Prior Period Adjustments Restatement [Line Items] Capitalization of internally developed software costs Capitalized Computer Software, Gross Capitalized Computer Software, Unamortized Capitalized Computer Software, Unamortized Capitalized Computer Software, Unamortized Amortization expense for capitalized internally developed software Capitalized Computer Software, Amortization Investment in privately held company Commission asset balance Commission Asset Commission Asset Deferred tax liability Deferred Tax Liabilities, Net Commission Expense Commission Expense Commission Expense Deferred Revenue Arrangement, by Type [Table] Deferred Revenue Arrangement, by Type [Table] Deferred Revenue Arrangement Type [Axis] Deferred Revenue Arrangement Type [Axis] Deferred Revenue [Domain] Deferred Revenue [Domain] ASC 606 Operating Leases Accounting Standards Update 2016-02 [Member] Deferred Revenue Arrangement [Line Items] Deferred Revenue Arrangement [Line Items] Deferred revenue, current Deferred revenue, noncurrent Total Deferred Revenue The Company and Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Operating Lease Expected Revenue Contract with Customer, Sales Channel [Axis] Contract with Customer, Sales Channel [Axis] Contract with Customer, Sales Channel [Domain] Contract with Customer, Sales Channel [Domain] Direct Sales Channel, Directly to Consumer [Member] Partner Sales Channel, Through Intermediary [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Revenues Revenue from Contract with Customer, Excluding Assessed Tax Revenue, Initial Application Period Cumulative Effect Transition [Table] Revenue, Initial Application Period Cumulative Effect Transition [Table] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] Subscription Revenue Subscription Revenue [Member] Subscription Revenue [Member] Revenue, Initial Application Period Cumulative Effect Transition [Line Items] Revenue, Initial Application Period Cumulative Effect Transition [Line Items] Amortization of commissions assets Amortization of Deferred Sales Commissions Capitalized contract costs Capitalized Contract Cost, Net Revenue recognized Unbilled contracts Unbilled Receivables, Not Billable United States Foreign Contracts expected to be billed remainder of year Unbilled Receivables, Expected To Be Billed In Remainder Of Year Unbilled Receivables, Expected To Be Billed In Remainder Of Year Unbilled Receivables, Expected To Be Billed In 2019 Unbilled Receivables, Expected To Be Billed In Year Two Unbilled Receivables, Expected To Be Billed In Year Two Unbilled Receivables, Expected To Be Billed In 2020 Unbilled Receivables, Expected To Be Billed In Year Three Unbilled Receivables, Expected To Be Billed In Year Three Unbilled Receivables, Expected To Be Billed In 2021 Unbilled Receivables, Expected To Be Billed In Year Four Unbilled Receivables, Expected To Be Billed In Year Four Unbilled Receivables, Expected To Be Billed In 2022 Unbilled Receivables, Expected To Be Billed In Year Five Unbilled Receivables, Expected To Be Billed In Year Five Unbilled Receivables, Expected To Be Billed Thereafter Unbilled Receivables, Expected To Be Billed Thereafter Unbilled Receivables, Expected To Be Billed Thereafter Unbilled Receivables, Not Billable Financing arrangement for data center storage equipment Capital Leased Assets, Gross Arrangement interest rate Capital Leased Assets, Interest Rate Capital Leased Assets, Interest Rate Rent expense Operating Leases, Rent Expense Deferred rent credit Deferred Rent Credit, Noncurrent Schedule of Operating Leased Assets [Table] Schedule of Operating Leased Assets [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Standby letter of credit Standby Letters of Credit [Member] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Domain] Lease Arrangement, Type [Domain] Headquarter Office Facility Headquarter Office Facility [Member] Headquarter Office Facility [Member] Operating Leased Assets] Operating Leased Assets [Line Items] Lease term (in years) Lessee, Operating Lease, Term of Contract Total lease commitment Letter of credit to secure the Company's lease obligations Line of Credit Facility, Maximum Borrowing Capacity Carrying value of intangible assets Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block] Intangible assets future periods amortization expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] 2018 (remaining three months) Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Five 2023 and thereafter Finite-Lived Intangible Assets, Amortization Expense, after Year Five Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Outstanding Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Beginning balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Canceled (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Ending balance (in shares) Vested and expected to vest (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Exercisable (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Weighted average exercise price, Beginning balance (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price 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 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 Weighted average exercise price, canceled (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Weighted average exercise price, Ending balance (in dollars per share) Weighted average exercise price, Vested and expected to vest (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Weighted average exercise price, Exercisable (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price Weighted Average Remaining Contractual Life Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term [Abstract] Weighted average remaining contractual life (in years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted Average Remaining Contractual Life (Years), Vested and Expected to Vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Weighted Average Remaining Contractual Life (Years), Exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value [Abstract] Aggregate intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Aggregate intrinsic value, Vested and expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Aggregate intrinsic value, Exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value Stockholder's Equity Stockholders' Equity Note Disclosure [Text Block] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Mature within One Year Available-for-sale Securities, Debt and Equity Maturities, Next Twelve Months, Fair Value Available-for-sale Securities, Debt and Equity Maturities, Next Twelve Months, Fair Value Mature after One Year through Two Years Available-for-sale Securities, Debt and Equity Maturities, Year One through Two, Fair Value Available-for-sale Securities, Debt and Equity Maturities, Year One through Two, Fair Value Mature over Two Years Available-for-sale Securities, Debt and Equity Maturities, After Year Two, Fair Value Available-for-sale Securities, Debt and Equity Maturities, After Year Two, Fair Value Fair Value Income Statement [Abstract] Revenues Revenues [Abstract] Cost of revenues Cost of Revenue Gross profit Gross Profit Operating expenses: Operating Expenses [Abstract] Research and development Research and Development Expense Sales and marketing Selling and Marketing Expense General and administrative General and Administrative Expense Total operating expenses Operating Expenses Income from operations Operating Income (Loss) Other income (expense), net: Other Income (Expense), Net [Abstract] Other Income (Expense), Net [Abstract] Interest expense Interest Expense Interest income Investment Income, Interest Other expense, net Other Nonoperating Income (Expense) Total other income, net Nonoperating Income (Expense) Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Net income Net income per share: Weighted average shares used in computing net income per share: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Diluted (shares) Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Cash Cash [Member] Money market funds Money Market Funds [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Cash and cash equivalents Cash and Cash Equivalents [Member] Short-term investments Available-for-sale Securities, Line Item [Member] Available-for-sale Securities, Line Item [Member] Long-term investments Long-Term Investments [Member] Long-Term Investments [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Amortized Cost Available-for-sale Securities, Amortized Cost Basis Unrealized Gains Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Unrealized Losses Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Fair Value Available-for-sale Securities, Current Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivative, number of instruments held Derivative, Number of Instruments Held Derivative, notional amount Derivative, Notional Amount Foreign currency contract, asset, fair value disclosure Foreign Currency Contract, Asset, Fair Value Disclosure Allowance for doubtful accounts receivable Preferred stock, par or stated value per share (USD per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, shares issued Preferred Stock, Shares Issued Preferred stock, shares outstanding Preferred Stock, Shares Outstanding Common stock, par or stated value per share (USD per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding