Share-based Compensation [Abstract] Employee Stock and Benefit Plans Compensation and Employee Benefit Plans [Text Block] Other Income and Expenses [Abstract] Other Income (Expense), Net Other Income and Other Expense Disclosure [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Geographical Area [Axis] Geographical [Axis] Segment, Geographical [Domain] Geographical [Domain] United States UNITED STATES Foreign Other Geographic Areas [Member] Other Geographic Areas [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Number of operating segments Number of Operating Segments Revenues Revenues Property and equipment, net Property, Plant and Equipment, Net Goodwill and Intangible Assets Disclosure [Abstract] 2016 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months 2017 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Five 2021 and thereafter Finite-Lived Intangible Assets, Amortization Expense, after Year Five Net Book Value Finite-Lived Intangible Assets, Net Schedule of Other Nonoperating Income (Expense) Schedule of Other Nonoperating Income (Expense) [Table Text Block] Income Tax Disclosure [Abstract] Schedule of Geographical Breakdown of Income (Loss) Before Provision for (Benefit From) Income Taxes Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Schedule of Provision for (Benefit From) Income Taxes Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule of Unrecognized Tax Benefits Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] 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] 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Securities, Line Item [Member] Available-for-sale Securities, Line Item [Member] Long-Term Investments Long-Term Investments [Member] Long-Term Investments [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] Cash Cash [Member] Money market funds Money Market Funds [Member] U.S. government agencies US Government Agencies Debt Securities [Member] Commercial paper Commercial Paper [Member] Corporate bonds Corporate Bond Securities [Member] Asset-backed securities Asset-backed Securities [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, total 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Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Award Type [Domain] Equity Award [Domain] Restricted Stock Units Restricted Stock Units (RSUs) [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 granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Weighted-average grant date fair value (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 Units vested and released in period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Units cancelled and forfeited during period (in shares) Share-based Compensation 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Nonoperating Income (Expense) Total other expense, net Nonoperating Income (Expense) Provision for (benefit from) income taxes Income Tax Expense (Benefit) Net income Net Income (Loss) Attributable to Parent Net income attributable to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Net income per share attributable to common stockholders: Basic (usd per share) Earnings Per Share, Basic Diluted (usd per share) Earnings Per Share, Diluted Weighted average shares used in computing net income per share attributable to common stockholders: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Property, Plant and Equipment [Abstract] Property and equipment Property, Plant and Equipment [Table Text Block] 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] Existing technology Developed Technology Rights [Member] Patent license Patents [Member] Non-competition agreements and other Non-competition Agreements and Other Intangible Assets [Member] [Member] Non-competition Agreements and Other Intangible Assets [Member] [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] Estimated Lives Finite-Lived Intangible Asset, Useful Life Cost Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Intangible assets not subject to amortization Indefinite-Lived Intangible Assets (Excluding Goodwill) Total intangible assets, net Intangible Assets, Net (Excluding Goodwill) Amortization of intangible assets Amortization of Intangible Assets Impairment of intangible assets Impairment of Intangible Assets, Finite-lived Goodwill Goodwill 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 investments Accretion (Amortization) of Discounts and Premiums, Investments Excess tax benefits from stock-based compensation Excess Tax Benefit from Share-based Compensation, Operating Activities Deferred income taxes Deferred Income Taxes and Tax Credits 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 noncurrent 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 investments Payments to Acquire Available-for-sale Securities Sales and maturities of investments Proceeds from Sale and Maturity of Available-for-sale Securities Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Capitalized software development costs Capitalized Software Development Costs Capitalized Software Developpment Costs Release of restricted cash Increase (Decrease) in Restricted Cash 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 Proceeds from early exercise of stock options Proceeds from Stock Options Exercised, Early Exercise Proceeds from Stock Options Exercised, Early Exercise Excess tax benefits from stock-based compensation Excess Tax Benefit from Share-based Compensation, Financing Activities Principal payments under capital lease obligations Repayments of Long-term Capital Lease Obligations Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Effect of exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash and Cash Equivalents Net increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of period Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents 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 Non-cash investing and financing activities Noncash Investing and Financing Items [Abstract] Purchases of property and equipment recorded in accounts payable and accrued liabilities Capital Expenditures Incurred but Not yet Paid Vesting of early exercised common stock options Adjustments to Additional Paid in Capital, Share-based Compensation, Stock Options, Requisite Service Period Recognition, Early Exercised Adjustments to Additional Paid in Capital, Share-based Compensation, Stock Options, Requisite Service Period Recognition, Early Exercised Accounting Policies [Abstract] The company and qualitative disclosure about market risk [Table] Derivative [Table] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Customer concentration risk Customer Concentration Risk [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Accounts receivable Accounts Receivable [Member] Software and software development costs Software and Software Development Costs [Member] Derivative, by Nature [Axis] Derivative, by Nature [Axis] Derivative, Name [Domain] Derivative, Name [Domain] Forward contracts Forward Contracts [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Scanner appliances Scanner appliances [Member] Scanner appliances [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] New Accounting Pronouncement, Early Adoption [Axis] New Accounting Pronouncement, Early Adoption [Axis] New Accounting Principles, Early Adoption [Domain] New Accounting Principles, Early Adoption [Domain] Effect of early adoption of accounting guidance New Accounting Pronouncement, Early Adoption, Effect [Member] The company and qualitative disclosure about market risk [Line Items] Derivative [Line Items] Concentration of Credit Risk Concentration of Credit Risk [Abstract] Concentration of Credit Risk [Abstract] Concentration risk, number of customers Concentration risk, number of customers Concentration risk, number of customers Property Equipment, Net Property, plant and equipment, useful life Property, Plant and Equipment, Useful Life Goodwill and Intangible Assets Goodwill and Intangible Assets, Net [Abstract] Goodwill and Intangible Assets, Net [Abstract] Finite-lived intangible asset, useful life Software Development Costs Research and Development [Abstract] Capitalized software development costs Cost of intangible assets Accumulated amortization of intangible assets Derivative Financial Instruments Summary of Derivative Instruments [Abstract] 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 Derivative instruments not designated as hedging instruments, gain Derivative Instruments Not Designated as Hedging Instruments, Gain Foreign currency transaction loss, before tax Foreign Currency Transaction Loss, before Tax Advertising Expenses Marketing and Advertising Expense [Abstract] Advertising expense Advertising Expense Foreign exchange losses Foreign Currency Transaction Gain (Loss), before Tax Income Taxes Current deferred tax assets Deferred Tax Assets, Net, Current Noncurrent deferred tax assets Deferred Tax Assets, Net, Noncurrent Current Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State Current State and Local Tax Expense (Benefit) Foreign Current Foreign Tax Expense (Benefit) Total current provision Current Income Tax Expense (Benefit) Deferred Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Foreign Deferred Foreign Income Tax Expense (Benefit) Total deferred provision (benefit) Deferred Income Tax Expense (Benefit) Provision for (benefit from) income taxes Stock-based employee compensation Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Fair value assumptions of options granted to employees Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Stock option activity Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Schedule of exercise price range, outstanding and vested Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table 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 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 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 Available-for-sale Securities Rent expense Operating Leases, Rent Expense Deferred rent credit, noncurrent Deferred Rent Credit, Noncurrent Statement of Financial Position [Abstract] Allowance for Doubtful Accounts Receivable Allowance for Doubtful Accounts Receivable Preferred Stock, Par Value (in dollars 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 (in dollars 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 Property and Equipment, net Property, Plant and Equipment Disclosure [Text Block] Schedule of Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Computer equipment Computer Equipment [Member] Computer software Computer Software, Intangible Asset [Member] Furniture, fixtures and equipment Furniture and Fixtures [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] Other fixed assets not placed in service Other Fixed Assets Not Placed in Service [Member] Other Fixed Assets Not Placed in Service [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 Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2000 Equity Incentive Plan 2000 Equity Incentive Plan [Member] 2000 Equity Incentive Plan [Member] Exercise Price Range [Axis] Exercise Price Range [Axis] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] $1.40 - $1.40 Exercise Price Range One [Member] Exercise Price Range One [Member] $1.90 - $1.90 Exercise Price Range Two [Member] Exercise Price Range Two [Member] $2.10 - $2.80 Exercise Price Range Three [Member] Exercise Price Range Three [Member] $3.80 - $3.80 Exercise Price Range Four [Member] Exercise Price Range Four [Member] $4.10 - $8.90 Exercise Price Range Five [Member] Exercise Price Range Five [Member] $9.40 - $16.68 Exercise Price Range Six [Member] Exercise Price Range Six [Member] $19.26 - $26.86 Exercise Price Range Seven [Member] Exercise Price Range Seven [Member] $30.58 - $30.58 Exercise Price Range Eight [Member] Exercise Price Range Eight [Member] $34.97 - $37.28 Exercise Price Range Nine [Member] Exercise Price Range Nine [Member] $40.68 - $52.14 Exercise Price Range Ten [Member] Exercise Price Range Ten [Member] Stock Options Employee Stock Option [Member] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Exercise price range, lower limit (in dollar per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit Exercise price range, upper limit (in dollar per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit Number of shares, outstanding Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options Weighted average exercise price per share, outstanding (in dollar per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price Weighted average remaining contractual life, outstanding Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term Number of shares, vested Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Vested Options Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Vested Options Weighted average exercise price per share, vested (in dollar per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Vested Options, Weighted Average Exercise Price Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Vested Options, Weighted Average Exercise Price Weighted average grant date fair value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Aggregate grant date fair value Share-based Compensation Arrangement by Share-based Payment Award, Options, Granted in Period, Total Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Granted in Period, Total Fair Value Intrinsic value of options exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value 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] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Numerator: Numerator [Abstract] Numerator [Abstract] Net income attributable to participating securities Participating Securities, Distributed and Undistributed Earnings (Loss), Basic Net income attributable to common stockholders - basic Net income attributable to common stockholders - diluted Net Income (Loss) Available to Common Stockholders, Diluted Denominator: Denominator [Abstract] Denominator [Abstract] Weighted-average shares used in computing net income per share attributable to common stockholders - basic Effect of potentially dilutive securities: Dilutive Securities, Effect on Basic Earnings Per Share [Abstract] Common stock options (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted - average shares used in computing net income (loss) per share attributable to common stockholders - diluted (in shares) Diluted (usd per share) Antidilutive Securities Antidilutive Securities [Abstract] Antidilutive Securities [Abstract] Common stock options (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Net Income Per Share Attributable to Common Stockholders Earnings Per Share [Text Block] Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Accumulated Deficit Retained Earnings [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance Stockholders' Equity Attributable to Parent Balance (in shares) Shares, Outstanding Change in net unrealized gain (loss) on investments Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Issuance of common stock upon exercise of stock options Stock Issued During Period, Value, Stock Options Exercised Issuance of common stock upon vesting of restricted stock units Stock Issued During Period, Value, Restricted Stock Award, Vested Stock Issued During Period, Value, Restricted Stock Award, Vested Issuance of common stock upon vesting of restricted stock units (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Vested Stock Issued During Period, Shares, Restricted Stock Award, Vested Issuance of common stock upon exercise of stock options (shares) Excess tax benefits from stock-based compensation Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Repurchase of unvested early exercised stock options Stock Repurchased During Period, Value Repurchase of unvested early exercised stock options (shares) Stock Repurchased During Period, Shares Issuance of common stock in exchange for services Stock Issued During Period, Value, Issued for Services Issuance of common stock in exchange for services (shares) Stock Issued During Period, Shares, Issued for Services Stock-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Balance Balance (in shares) Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Assets Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Short-term investments Short-term Investments Accounts receivable, net of allowance of $769 and $590 at December 31, 2015 and 2014, respectively Accounts Receivable, Net, Current Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Long-term investments Long-term Investments Deferred tax assets, net Intangible assets, net 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 5) Commitments and Contingencies Stockholders’ equity: Preferred stock: $0.001 par value; 20,000,000 shares authorized, no shares issued and outstanding at December 31, 2015 and 2014 Preferred Stock, Value, Issued Common stock, $0.001 par value; 1,000,000,000 shares authorized, 34,414,631 and 33,594,285 shares issued and outstanding at December 31, 2015 and 2014, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated deficit Retained Earnings (Accumulated Deficit) Total stockholders’ equity Total liabilities and stockholders’ equity Liabilities and Equity 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] Quarterly Financial Information Disclosure [Abstract] Income Tax [Table] Income Tax [Table] Income Tax [Table] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] Federal and State Jurisdictions [Member] Domestic Tax Authority [Member] Income Tax [Line Items] Income Tax [Line Items] Income Tax Other income (expense), net Provision for (benefit from) income taxes Earnings Per Share [Abstract] Basic (in usd per share) Expected term Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Schedule of Quarterly Financial Information Schedule of Quarterly Financial Information [Table Text Block] Schedule of Future Minimum Lease Payments for Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Segment Information and Information about Geographic Area Segment Reporting Disclosure [Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] 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] Valuation and Qualifying Accounts Disclosure [Table] Valuation and Qualifying Accounts Disclosure [Table] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves [Domain] Valuation Allowances and Reserves [Domain] Allowance for Doubtful Accounts Allowance for Doubtful Accounts [Member] Valuation and Qualifying Accounts Disclosure [Line Items] Valuation and Qualifying Accounts Disclosure [Line Items] Movement in Valuation Allowances and Reserves [Roll Forward] Movement in Valuation Allowances and Reserves [Roll Forward] Balance at Beginning of Year Valuation Allowances and Reserves, Balance Charged to Costs and Expenses Valuation Allowances and Reserves, Charged to Cost and Expense Deductions and Other Valuation Allowances and Reserves, Deductions Balance at End of Year Internal 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Reconciliation, Tax Credit, Research, Amount Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract] Effective Income Tax Rate Reconciliation, Percent [Abstract] Federal statutory rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent State taxes Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Stock-based compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Percent Foreign source income Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Percent Change in valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Incremental federal rate benefit previously not recognized Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent Federal and state research and development credit Effective Income Tax Rate Reconciliation, Tax Credit, Research, Percent Other Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Provision for (benefit from) income taxes Effective Income Tax Rate Reconciliation, Percent 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 Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Public Float Entity Public Float Statement of Comprehensive Income [Abstract] Change in net unrealized gain (loss) on investments, net of tax Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Less: reclassification adjustment for net realized gain included in net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Net change, net of tax Other comprehensive income (loss), net Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Equity Incentive Plan Annual Increase Feature [Axis] Equity Incentive Plan Annual Increase Feature [Axis] Equity Incentive Plan Annual Increase Feature [Axis] Equity Incentive Plan Annual Increase Feature [Domain] Equity Incentive Plan Annual Increase Feature [Domain] [Domain] for Equity Incentive Plan Annual Increase Feature [Axis] Increase of Number of Shares Option Increase of Number of Shares Option [Member] Increase of Number of Shares Option [Member] Increase of Percentage of Shares Outstanding Option Increase of Percentage of Shares Outstanding Option [Member] Increase of Percentage of Shares Outstanding Option [Member] 2012 Equity Incentive Plan 2012 Equity Incentive Plan [Member] 2012 Equity Incentive Plan [Member] Number of shares authorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Equity incentive plan annual increase (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Annual Increase, Shares Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Annual Increase, Shares Equity incentive plan, annual increase, percent of shares outstanding Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Annual Increase, Percent of Shares Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Annual Increase, Percent of Shares Outstanding Award vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Term of award Share-based Compensation Arrangement by Share-based Payment Award, Term of Award Share-based Compensation Arrangement by Share-based Payment Award, Term of Award Expiration period Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Number of shares available for grant Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Award strike price as a percentage of market value Share-based Compensation Arrangement by Share-based Payment Award, Award Strike Price as a Percentage of Market Value Share-based Compensation Arrangement by Share-based Payment Award, Award Strike Price as a Percentage of Market Value Number of shares available for issuance Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Issuance Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Issuance 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] Use of estimates Use of Estimates, Policy [Policy Text Block] Concentration of credit risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Cash, cash equivalents and short-term and long-term investments Cash, Cash Equivalents and Short-Term and Long-Term Investments Policy [Policy Text Block] Cash, Cash Equivalents and Short-Term and Long-Term Investments Policy [Policy Text Block] Accounts receivable Trade and Other Accounts Receivable, Policy [Policy Text Block] Property and equipment, net Property, Plant and Equipment, Policy [Policy Text Block] Impairment of long-lived assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Goodwill and intangible assets Goodwill and Intangible Assets, Policy [Policy Text Block] Software development cost Research, Development, and Computer Software, Policy [Policy Text Block] Derivative financial instruments Derivatives, Reporting of Derivative Activity [Policy Text Block] Share-based compensation Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Revenue recognition Revenue Recognition, Policy [Policy Text Block] Advertising expenses Advertising Costs, Policy [Policy Text Block] Income taxes Income Tax, Policy [Policy Text Block] Comprehensive income (loss) Comprehensive Income, Policy [Policy Text Block] Foreign currency translation and transactions Foreign Currency Transactions and Translations Policy [Policy Text Block] Fair value measurement Fair Value Measurement, Policy [Policy Text Block] Net income per share attributable to common stockholders Earnings Per Share, Policy [Policy Text Block] Recent accounting pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Revenues and property and equipment, net, by geographic area Schedule of Segment Reporting Information, by Segment [Table Text Block] Stockholders' Equity [Table] Stockholders Equity [Table] Stockholders Equity [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Preferred Stock Preferred Stock [Member] Stockholders Equity [Line Items] Stockholders Equity [Line Items] [Line Items] for Stockholders Equity [Table] Common Stock Shareholders' Equity, Common Stock [Abstract] Shareholders' Equity, Common Stock [Abstract] Options and RSUs outstanding under equity incentive plans Shares available for future grants under an equity incentive plan Total shares reserved for future issuance Common Stock, Capital Shares Reserved for Future Issuance Preferred Stock Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Preferred stock, shares authorized Preferred stock, par value per share (in dollars per share) Schedule of Cash and Cash Equivalents, Available-for-sale Securities Reconciliation Available-for-sale Securities [Table Text Block] Schedule of Assets Measured on Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Schedule of Investments Classified by Contractual Maturity Investments Classified by Contractual Maturity Date [Table Text Block] Other income (expense) Other non operating income expense other Other non operating income expense other Other income (expense), net 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] Unrecognized tax benefits beginning balance Unrecognized Tax Benefits Gross increase for tax positions of prior years Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Gross decrease for tax positions of prior years Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Gross increase for tax positions of current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Lapse of statute of limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Total unrecognized tax benefits 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] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Assets, Fair Value Disclosure [Abstract] Assets, Fair Value Disclosure [Abstract] Available-for-sale securities, fair value Quarterly Financial Information (Unaudited) Quarterly Financial Information [Text Block] The Company and Summary of Significant Accounting Policies Business Description and Accounting Policies [Text Block]