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 realized gain (loss) on investments Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Amounts reclassified for net realized gain (loss) included in net income 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 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] 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 Property, Plant and Equipment, Net Depreciation and amortization expense Depreciation, Depletion And Amortization, Excluding Intangible Asset Amortization Depreciation, Depletion And Amortization, Excluding Intangible Asset Amortization 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 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 Revenues Revenues Property and equipment, net Property and equipment, net Property, Plant and Equipment [Table Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] 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, Vested and expected to vest (in years) 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, Exercisable (in years) 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 Segment Information and Information about Geographic Area Segment Reporting Disclosure [Text Block] Statement of Comprehensive Income [Abstract] Net income Net Income (Loss) Attributable to Parent Change in foreign currency translation loss, net of zero tax Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Available-for-sale investments: Available-for-sale Securities [Abstract] Change in net unrealized gain (loss) on investments, net of tax Less: reclassification adjustment for net realized gain included in net income Net change, 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 Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets, Net Goodwill and Intangible Assets Disclosure [Text Block] Commitments and Contingencies Disclosure [Abstract] Operating Leases Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] Remainder of 2017 Operating Leases, Future Minimum Payments, Remainder of Fiscal Year 2018 Operating Leases, Future Minimum Payments, Due in Two Years 2019 Operating Leases, Future Minimum Payments, Due in Three Years 2020 Operating Leases, Future Minimum Payments, Due in Four Years 2021 Operating Leases, Future Minimum Payments, Due in Five Years 2022 and thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total minimum lease payments Operating Leases, Future Minimum Payments Due 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] Reclassification Reclassification, 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] 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 Tax Expense (Benefit) 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 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 Purchase of business Payments to Acquire Businesses, Gross 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 Excess tax benefits from stock-based compensation Excess Tax Benefit from Share-based Compensation, Financing Activities Payments for taxes related to net share settlement of equity awards Payments Related to Tax Withholding for Share-based Compensation Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities 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 cash flow disclosures: Supplemental Cash Flow Information [Abstract] Purchases of property and equipment recorded in accounts payable and accrued liabilities Capital Expenditures Incurred but Not yet Paid Cash paid for income taxes Income Taxes Paid Not yet received tenant allowance recorded in other assets, accrued liabilities and other non-current liabilities Increase (Decrease) In Tenant Improvements Receivable Increase (Decrease) In Tenant Improvements Receivable Earnings Per Share [Abstract] Numerator: Numerator [Abstract] Numerator [Abstract] 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 Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Other Income and Expenses [Abstract] Foreign exchange gain (loss) Foreign Currency Transaction Gain (Loss) Including Derivatives, Before Tax Foreign Currency Transaction Gain (Loss) Including Derivatives, Before Tax Other income (expense) Other non operating income expense other Other non operating income expense other Other expense, net Other Nonoperating Income (Expense) 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] 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] 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 Intangible Assets, Net (Excluding Goodwill) Amortization of intangible assets Amortization of Intangible Assets Goodwill Goodwill 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] 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 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 Property and Equipment, Net Property, Plant and Equipment Disclosure [Text Block] Schedule of Future Minimum Lease Payments for Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] 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 Fair Value of Financial Instruments Fair Value Disclosures [Text Block] The Company and Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Stock-based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Statement of Financial Position [Abstract] Allowance for doubtful accounts receivable 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 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 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 Total other income (expense), net Nonoperating Income (Expense) Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest (Benefit from) provision for income taxes Income Tax Expense (Benefit) 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) 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] Nevis Networks Nevis Networks [Member] Nevis Networks [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Total purchase price Business Combination, Consideration Transferred 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 Net Income Per Share Earnings Per Share [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 $658 and $702 as of September 30, 2017 and December 31, 2016, 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 Deferred Tax Assets, Net, Noncurrent Intangible assets, net 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 6) 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, 2017 and December 31, 2016 Preferred Stock, Value, Issued Common stock, $0.001 par value; 1,000,000,000 shares authorized; 37,896,671 and 35,841,001 shares issued and outstanding at September 30, 2017 and December 31, 2016 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 (Accumulated deficit) Retained Earnings (Accumulated Deficit) Total stockholders’ equity Total liabilities and stockholders’ equity Liabilities and Equity 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] Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU 2016-09 Accounting Standards Update 2016-09 [Member] Accounting Standards Update 2016-09 [Member] Retained Earnings Retained Earnings [Member] Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards [Line Items] Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Benefit recognized for excess tax benefits related to stock-based compensation Effective Income Tax Rate Reconciliation, Share-Based Compensation, Excess Tax Benefit, Amount Effective Income Tax Rate Reconciliation, Share-Based Compensation, Excess Tax Benefit, Amount Cumulative effect adjustment Cumulative Effect of New Accounting Principle in Period of Adoption Decrease to deferred tax assets Deferred Income Tax Assets, Net Unrecognized tax benefits Unrecognized Tax Benefits Unrecognized tax benefits that would impact effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate 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 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 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] Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Restatement Adjustment Restatement Adjustment [Member] Reclassification Error Corrections and Prior Period Adjustments Restatement [Line Items] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivative, by Nature [Axis] Derivative Instrument [Axis] Derivative, Name [Domain] Derivative Contract [Domain] Forward Contracts Forward Contracts [Member] 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 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 Employee stock-based compensation Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Stock option activity Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Restricted stock units activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Schedule of Other Nonoperating Income (Expense) Schedule of Other Nonoperating Income (Expense) [Table Text Block] 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] 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 Leasing Arrangements, Operating Leases, Term of Contract Total lease commitment Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Net loss from forward contracts Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Other foreign currency transactions gain Foreign Currency Transaction Gain (Loss), before Tax Total foreign exchange gain (loss), net Remainder of 2017 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 2022 and thereafter Finite-Lived Intangible Assets, Amortization Expense, after Year Five 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 Other Income (Expense), Net Other Income and Other Expense Disclosure [Text Block] 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] Business Combination Business Combination Disclosure [Text Block]