Goodwill and Intangible Assets Disclosure [Abstract] Schedule of changes in the carrying amount of goodwill Schedule of Goodwill [Table Text Block] Summary of gross carrying amounts and accumulated amortization of intangible assets - finite lived Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block] Summary of gross carrying amounts of intangible assets - indefinite lived Schedule of Acquired Indefinite-lived Intangible Assets by Major Class [Table Text Block] Schedule of future amortization expense related to finite-lived intangible assets Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Statement of Financial Position [Abstract] Accounts receivable, allowance Allowance for Doubtful Accounts Receivable Redeemable convertible preferred stock, shares issued Temporary Equity, Shares Issued Redeemable convertible preferred stock, shares outstanding Temporary Equity, Shares Outstanding Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Commitments and Contingencies Disclosure [Abstract] Content acquisition costs Payments for Royalties Amortization of prepaid content acquisition costs Amortization of Advance Royalty Total future minimum guarantee payments Royalty Guarantees, Commitments, Amount Future minimum guarantee commitments to be paid this year Royalty Guarantees, Commitments, Future Minimum Payments Due, Remainder of Fiscal Year Royalty Guarantees, Commitments, Future Minimum Payments Due, Remainder of Fiscal Year Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Indemnification agreement Indemnification Agreement [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Accrued indemnification liabilities Loss Contingency Accrual Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Pandora Pandora [Member] Pandora [Member] Ticketfly Ticketfly, Inc. [Member] Ticketfly, Inc. [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Balance as of December 31, 2016 Goodwill Goodwill impairment Goodwill, Impairment Loss Goodwill related to disposed assets Disposal Group, Including Discontinued Operation, Goodwill Effect of currency translation adjustment Goodwill, Translation and Purchase Accounting Adjustments Balance as of September 30, 2017 Assets Assets [Abstract] Current assets Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Short-term investments Short-term Investments Accounts receivable, net of allowance of $3,633 at December 31, 2016 and $5,854 at September 30, 2017 Receivables, Net, Current Prepaid content acquisition costs Prepaid Royalties Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Convertible promissory note receivable Receivable with Imputed Interest, Net Amount Long-term investments Long-term Investments Property and equipment, net Property, Plant and Equipment, Net Goodwill Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Other long-term assets Other Assets, Noncurrent Total assets Assets Liabilities, redeemable convertible preferred stock and stockholders’ equity Liabilities and Equity [Abstract] Current liabilities Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued liabilities Accrued Liabilities, Current Accrued content acquisition costs Accrued Royalties, Current Accrued compensation Employee-related Liabilities, Current Deferred revenue Deferred Revenue, Current Other current liabilities Other Liabilities, Current Total current liabilities Liabilities, Current Long-term debt, net Long-term Debt Other long-term liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Redeemable convertible preferred stock: 480,000 shares issued and outstanding at September 30, 2017 Temporary Equity, Carrying Amount, Including Portion Attributable to Noncontrolling Interests Stockholders’ equity Stockholders' Equity Attributable to Parent [Abstract] Common stock: 235,162,757 shares issued and outstanding at December 31, 2016 and 248,681,713 at September 30, 2017 Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Accumulated deficit Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders’ equity Stockholders' Equity Attributable to Parent Total liabilities, redeemable convertible preferred stock and stockholders’ equity Liabilities and Equity Restructuring and Related Activities [Abstract] Reduction in force Restructuring and Related Cost, Number of Positions Eliminated, Period Percent Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Employee severance and benefits costs Employee Severance [Member] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Expected cash expenditures Restructuring and Related Cost, Incurred Cost Total reduction in force expenses Restructuring and Related Cost, Cost Incurred to Date Reduction of headcount, employees Restructuring and Related Cost, Number of Positions Eliminated Earnings Per Share [Abstract] Net Loss Per Common Share Earnings Per Share [Text Block] Cash and Cash Equivalents [Abstract] Cash, Cash Equivalents and Investments Cash, Cash Equivalents, and Marketable Securities [Text Block] Temporary Equity Disclosure [Abstract] Temporary Equity, by Class of Stock [Table] Temporary Equity, by Class of Stock [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series A convertible preferred stock Series A Preferred Stock [Member] Sale of Stock [Axis] Sale of Stock [Axis] Sale of Stock [Domain] Sale of Stock [Domain] Initial closing Initial Closing [Member] Initial Closing [Member] Second closing Closing Upon Certain Regulatory Approvals [Member] Closing Upon Certain Regulatory Approvals [Member] Temporary Equity [Line Items] Temporary Equity [Line Items] Agreement to sell shares (in shares) Temporary Equity, Share Subscriptions Share price (in dollars per share) Shares Issued, Price Per Share Agreement to sell shares Temporary Equity, Shares Subscribed but Unissued, Subscriptions Receivable Proceeds from issuance of redeemable convertible preferred stock Proceeds from Issuance of Convertible Preferred Stock Shares conversion per share Convertible Preferred Stock, Shares Issued upon Conversion Conversion price (in dollars per share) Preferred Stock, Initial Conversion Price Per Share Preferred Stock, Initial Conversion Price Per Share Quarterly dividend rate, percentage Preferred Stock, Dividend Rate, Percentage Right to redeem, period Convertible Preferred Stock, Conversion Redemption Right, Period Convertible Preferred Stock, Conversion Redemption Right, Period Holder right to redeem, period Convertible Preferred Stock, Conversion Redemption Holder Right, Period Convertible Preferred Stock, Conversion Redemption Holder Right, Period Redemption percentage Convertible Preferred Stock, Conversion Redemption, Holder Right, Percent Convertible Preferred Stock, Conversion Redemption, Holder Right, Percent Contract termination fee and related legal and professional fees Gain (Loss) on Contract Termination Adjusted Cost Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract] Due in one year or less Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis Due after one year through three years Available For Sale Securities, Debt Maturities after One through Three Years, Amortized Cost Represents the amount of available-for-sale debt securities at cost, net of adjustments, maturing in the second fiscal year through the three fiscal years following the latest fiscal year. Total Available-for-sale Debt Securities, Amortized Cost Basis Fair Value Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract] Due in one year or less Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value Due after one year through three years Available For Sale Securities, Debt Maturities after One through Three Years, Fair Value Represents the amount of available-for-sale debt securities at fair value maturing in the second fiscal year through the three fiscal years following the latest fiscal year. Total Available-for-sale Securities, Debt Securities Series A redeemable convertible preferred stock Temporary Equity, Stock Issued During Period, Value, New Issues Issuance costs Payments of Stock Issuance Costs Accretion of issuance costs Accretion Expense Stock dividend payable to preferred stockholders Dividends Payable Redeemable convertible preferred stock Temporary Equity, Carrying Amount, Attributable to Parent Discontinued Operations and Disposal Groups [Abstract] Dispositions Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Schedule of the computation of historical basic and diluted net loss per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of potential common shares outstanding excluded from the computation of diluted net loss per share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Fair Value Disclosures [Abstract] Schedule of fair value of financial assets and liabilities inputs Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Sold Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] KXMZ KXMZ [Member] KXMZ [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Total purchase price Disposal Group, Including Discontinued Operation, Consideration Cash portion of purchase price Disposal Group, Including Discontinued Operation, Consideration, Cash Disposal Group, Including Discontinued Operation, Consideration, Cash Convertible subordinated promissory note Disposal Group, Including Discontinued Operation, Consideration, Notes Receivable Disposal Group, Including Discontinued Operation, Consideration, Notes Receivable Unamortized discount Receivable with Imputed Interest, Discount Costs to sell Business Acquisition, Transaction Costs Working capital and certain indemnification provisions adjustments Disposal Group, Including Discontinued Operation, Consideration Adjustments, Working Capital Disposal Group, Including Discontinued Operation, Consideration Adjustments, Working Capital Net purchase price Disposal Group, Including Discontinued Operation, Net Purchase Price Disposal Group, Including Discontinued Operation, Net Purchase Price Asset Impairment Charges Asset Impairment Charges Fair value of net assets Disposal Group, Including Discontinued Operation, Fair Value Of Net Assets Disposal Group, Including Discontinued Operation, Fair Value Of Net Assets Loss on sale Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal Proceeds from sales of subsidiaries, net of cash Proceeds from Divestiture of Businesses, Net of Cash Divested Cash held for sale Cash Divested from Deconsolidation Cash price adjustments Disposal Group, Including Discontinued Operation, Consideration Adjustments, Cash Price Disposal Group, Including Discontinued Operation, Consideration Adjustments, Cash Price Number of reportable segments Number of Reportable Segments Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Debt Disclosure [Abstract] Schedule of long-term debt Schedule of Long-term Debt Instruments [Table Text Block] Summary of the effective interest rate, contractually stated interest expense and costs related to amortization of discount for the Notes Convertible Debt [Table 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] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Stock options Employee And Non Employee Stock Options [Member] An arrangement whereby an employee and non-employee is entitled to receive in the future, subject to vesting and other restrictions, a number of shares in the entity at a specified price, as defined in the agreement. Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Stock-based compensation expense Allocated Share-based Compensation Expense Common stock issued (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Debt Instruments Debt Disclosure [Text Block] Income Statement [Abstract] Revenue Revenues [Abstract] Advertising Advertising Revenue Subscription and other Subscription and Circulation Revenue Ticketing service Sales Revenue, Services, Net Total revenue Revenue, Net Cost of revenue Cost of Revenue [Abstract] Cost of revenue—Content acquisition costs Direct Operating Cost, Royalty Expense Cost of revenue—Other Other Cost of Operating Revenue Cost of revenue—Ticketing service Cost of Services Total cost of revenue Cost of Revenue Gross profit Gross Profit Operating expenses Operating Expenses [Abstract] Product development Research and Development Expense (Excluding Acquired in Process Cost) Sales and marketing Selling and Marketing Expense General and administrative General and Administrative Expense Goodwill impairment Contract termination (benefit) fees Total operating expenses Operating Expenses Loss from operations Operating Income (Loss) Interest expense Interest Expense Other income, net Other Nonoperating Income Total other expense, net Other Nonoperating Income (Expense) Loss before (provision for) benefit from income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest (Provision for) benefit from income taxes Income Tax Expense (Benefit) Net loss Net Income (Loss) Attributable to Parent Net loss available to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Bbasic and diluted net loss per common share (in dollars per share) Earnings Per Share, Basic and Diluted Weighted-average basic and diluted common shares Weighted Average Number of Shares Outstanding, Basic and Diluted Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Line of Credit Facility [Table] Line of Credit Facility [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Convertible debt Convertible Debt [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Notes Convertible Senior Notes Due 2020 [Member] Convertible Senior Notes Due 2020 [Member] Debt Instruments Line of Credit Facility [Line Items] Aggregate principal amount Debt Instrument, Face Amount Unrealized gain Debt Instrument, Interest Rate, Stated Percentage Net proceeds from sale of debt Proceeds from Debt, Net of Issuance Costs Payments for capped call transactions Payments for Derivative Instrument, Financing Activities Debt instrument, conversion price (in dollars per share) Debt Instrument, Convertible, Conversion Price Value of debt Debt Instrument, Fair Value Disclosure Closing price of common stock (in dollars per share) Share Price Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] 1.75% convertible senior notes due 2020 Debt Instrument [Line Items] Debt Instrument [Line Items] Shares issued, shares Stock Issued During Period, Shares, New Issues Schedule of Goodwill [Table] Schedule of Goodwill [Table] Ticketfly and KXMZ Ticketfly, Inc. and KXMZ [Member] Ticketfly, Inc. and KXMZ [Member] Goodwill [Line Items] Goodwill [Line Items] Asset Impairment Charges Amortization expense of intangible assets Amortization of Intangible Assets RSUs Restricted Stock Units (RSUs) [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Schedule of cash, cash equivalents and investments Cash, Cash Equivalents and Investments [Table Text Block] Summary of available-for-sale securities' adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category Schedule of Available-for-sale Securities Reconciliation [Table Text Block] Schedule of available-for-sale investments by contractual maturity date Investments Classified by Contractual Maturity Date [Table Text Block] Summary of available-for-sale securities' fair value and gross unrealized losses Available-for-sale Securities [Table Text Block] Statement of Cash Flows [Abstract] Operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Net loss Adjustments to reconcile net loss to net cash used in operating activities Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Loss on sales of subsidiaries Depreciation and amortization Depreciation, Depletion and Amortization Stock-based compensation Share-based Compensation Amortization of premium on investments, net Amortization Of Premium On Investments, Net Amortization Of Premium On Investments, Net Accretion of discount on convertible promissory note receivable Accretion Of Discount On Convertible Promissory Note Receivable Accretion Of Discount On Convertible Promissory Note Receivable Other operating activities Other Operating Activities, Cash Flow Statement Amortization of debt discount Amortization of Debt Issuance Costs and Discounts Interest income Interest Income, Operating Provision for bad debt Provision for Doubtful Accounts Changes in operating assets and liabilities Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Prepaid content acquisition costs Increase (Decrease) in Prepaid Royalties Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Accounts payable, accrued and other current liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Accrued content acquisition costs Increase (Decrease) in Royalties Payable Accrued compensation Increase (Decrease) in Employee Related Liabilities Other long-term liabilities Increase (Decrease) in Other Noncurrent Liabilities Deferred revenue Increase (Decrease) in Deferred Revenue Reimbursement of cost of leasehold improvements Payments for (Proceeds from) Tenant Allowance Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Internal-use software costs Payments to Develop Software Changes in restricted cash Increase (Decrease) in Restricted Cash Purchases of investments Payments to Acquire Investments Proceeds from maturities of investments Proceeds from Sale, Maturity and Collection of Investments Proceeds from sales of investments Proceeds from Sale of Available-for-sale Securities Payments related to acquisitions, net of cash acquired Payments to Acquire Businesses, Gross Net cash (used in) provided by investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations Financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Payments of issuance costs Payments of Debt Issuance Costs Repayment of debt arrangements Repayments of Long-term Lines of Credit Borrowings under debt arrangements Proceeds from Long-term Lines of Credit Proceeds from employee stock purchase plan Proceeds from Stock Plans Proceeds from exercise of stock options Proceeds from Issuance of Common Stock Tax payments from net share settlements of restricted stock units Payments Related to Tax Withholding for Share-based Compensation Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations Effect of exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash and Cash Equivalents Net (decrease) 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 end of period Supplemental disclosures of cash flow information Supplemental Cash Flow Information [Abstract] Cash paid during the period for interest Interest Paid Purchases of property and equipment recorded in accounts payable and accrued liabilities Capital Expenditures Incurred but Not yet Paid Accretion of preferred stock issuance costs Stock dividend payable to preferred stockholders Dividends, Preferred Stock Fair value of convertible promissory note receivable received as partial consideration for sale of subsidiary Notes Issued Receivables [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Convertible promissory note Notes Receivable [Member] Convertible promissory note Convertible Subordinated Debt [Member] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Note term Notes Issued, Term Notes Issued, Term Stated interest rate Receivable, Interest Rate, Stated Percentage Receivable, Interest Rate, Stated Percentage Interest receivable Interest Receivable Amortization of discount Receivables with Imputed Interest, Amortization Amount Loss before benefit from (provision for) income taxes Assets Disposal Group, Including Discontinued Operation, Assets [Abstract] Cash and cash equivalents Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents Accounts receivable, net Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net Prepaid expenses and other current assets Disposal Group, Including Discontinued Operation, Prepaid and Other Assets Property and equipment, net Disposal Group, Including Discontinued Operation, Property, Plant and Equipment Goodwill Intangible assets, net Disposal Group, Including Discontinued Operation, Intangible Assets Other long-term assets Disposal Group, Including Discontinued Operation, Other Assets Total assets Disposal Group, Including Discontinued Operation, Assets Liabilities Disposal Group, Including Discontinued Operation, Liabilities [Abstract] Accounts payable, accrued liabilities and accrued compensation Disposal Group, Including Discontinued Operation, Accounts Payable and Accrued Liabilities Other current liabilities Disposal Group, Including Discontinued Operation, Other Liabilities, Current Other long-term liabilities Disposal Group, Including Discontinued Operation, Other Liabilities, Noncurrent Total liabilities Disposal Group, Including Discontinued Operation, Liabilities 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] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Cost of revenue—Other Cost of Sales [Member] Cost of revenue—Ticketing service Service And Processing Costs [Member] Service And Processing Costs [Member] Product development Research and Development Expense [Member] Sales and marketing Selling and Marketing Expense [Member] General and administrative General and Administrative Expense [Member] Executive severance Stock-based compensation expenses: Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Total stock-based compensation expense Statement of Comprehensive Income [Abstract] Change in foreign currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Change in net unrealized loss on marketable securities Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Other comprehensive loss Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Total comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Schedule of redeemable convertible preferred stock Schedule of Stock by Class [Table Text Block] PSUs Performance Shares [Member] Vesting [Axis] Vesting [Axis] Vesting [Domain] Vesting [Domain] One-Year Performance Period Share-based Compensation Award, Tranche One [Member] Requisite service period Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period Vesting percent Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Trailing average stock price period Share-Based Compensation Arrangement By Share-Based Payment Award, Determination Period At End Of Performance Period Share-Based Compensation Arrangement By Share-Based Payment Award, Determination Period At End Of Performance Period 90 Day trailing stock price to vest (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Performance Shares, 90 Day Trailing Stock Price to Vest Share-based Compensation Arrangement by Share-based Payment Award, Performance Shares, 90 Day Trailing Stock Price to Vest Grants in period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Grant date fair value Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Grants In Period, Total Grant Date Fair Value Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Grants In Period, Total Grant Date Fair Value Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] 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] Corporate debt securities Corporate Debt Securities [Member] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] Twelve Months or Less Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value More than Twelve Months Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Total Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Gross Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] Twelve Months or Less Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss More than Twelve Months Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Total Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss Stock-based Compensation Plans and Awards Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Valuation Technique [Axis] Valuation Technique [Axis] Valuation Technique [Domain] Valuation Technique [Domain] Black Scholes Options Pricing Model Black Scholes Options Pricing Model [Member] Represents information pertaining to the Black-Scholes options pricing model, a valuation method used in the computation of fair value of stock options. Employee stock Employee Stock [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Expected life (in years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Risk-free interest rate, minimum Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum Risk-free interest rate, maximum Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected volatility, minimum Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum Expected volatility, maximum Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum Expected dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Fair Value Fair Value Disclosures [Text Block] Schedule of carrying amounts of major classes of assets and liabilities and loss before income taxes Disposal Groups, Including Discontinued Operations [Table Text Block] Investment Holdings [Table] Investment Holdings [Table] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Cash Cash [Member] Money market funds Money Market Funds [Member] Cash, Cash Equivalents and Investments Investment Holdings [Line Items] Cash and cash equivalents Short-term investments Long-term investments Cash, cash equivalents and investments Cash, Cash Equivalents and Investments. Represents the amount of cash and cash equivalents and investments as of the balance sheet date. Numerator Net Income (Loss) Attributable to Parent [Abstract] Less: Stock dividend payable and transaction costs Redeemable Preferred Stock Dividends Net loss available to common stockholders Denominator Weighted Average Number of Shares Outstanding, Diluted [Abstract] Net loss per common share, basic and diluted (in dollars per share) Market Stock Units (MSUs) Market Stock Units (MSUs) [Member] Market Stock Units (MSUs) [Member] Two-Year Performance Period Share-based Compensation Award, Tranche Two [Member] Three-Year Performance Period Share-based Compensation Award, Tranche Three [Member] Number of performance periods Share-Based Compensation Arrangement By Share-Based Payment Award, Number Of Performance Periods Share-Based Compensation Arrangement By Share-Based Payment Award, Number Of Performance Periods TSR prior to beginning of performance period Share-Based Compensation Arrangement By Share-Based Payment Award, Determination Period Before Beginning Of Performance Period Share-Based Compensation Arrangement By Share-Based Payment Award, Determination Period Before Beginning Of Performance Period TSR at end of performance period Performance multiplier, percentage point decrease Share-Based Compensation Arrangement By Share-Based Payment Award, Performance Multiplier, Percentage Decrease Share-Based Compensation Arrangement By Share-Based Payment Award, Performance Multiplier, Percentage Decrease Performance multiplier Share-Based Compensation Arrangement By Share-Based Payment Award, Performance Multiplier Share-Based Compensation Arrangement By Share-Based Payment Award, Performance Multiplier Performance multiplier, percentage point increase Share-Based Compensation Arrangement By Share-Based Payment Award, Performance Multiplier, Percentage Increase Share-Based Compensation Arrangement By Share-Based Payment Award, Performance Multiplier, Percentage Increase TSR decline (percent) Total Shareholder Return, Percentage Decrease Total Shareholder Return, Percentage Decrease 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] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Pro Forma Pro Forma [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Additional Paid-in Capital Additional Paid-in Capital [Member] Deferred tax asset Deferred Tax Assets, Net of Valuation Allowance Cumulative effect Cumulative Effect of New Accounting Principle in Period of Adoption Number of owned securities that were in an unrealized loss position Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions Other-than-temporary investment losses Other than Temporary Impairment Losses, Investments Unrealized losses deemed to be other-than-temporary, recognized Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities 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 Thereafter Finite-Lived Intangible Assets, Amortization Expense, after Year Five Net Carrying Value Finite-Lived Intangible Assets, Net 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] Options to purchase common stock Restricted stock units Performance awards Anti-dilutive securities Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Total common stock equivalents (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Restructuring Charges Restructuring and Related Activities Disclosure [Text Block] Schedule of Interest Rates And Amortization Discount Schedule Of Interest Rates And Amortization Discount [Table Text Block] Schedule Of Interest Rates And Amortization Discount [Table Text Block] Schedule of Acquired Indefinite-lived Intangible Assets by Major Class [Table] Schedule of Acquired Indefinite-lived Intangible Assets by Major Class [Table] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-lived Intangible Assets, Major Class Name [Domain] FCC license - Broadcast Radio Licensing Agreements [Member] Acquired Indefinite-lived Intangible Assets [Line Items] Acquired Indefinite-lived Intangible Assets [Line Items] Indefinite-lived intangible assets Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract] Net Carrying Value Indefinite-Lived Intangible Assets (Excluding Goodwill) Total disposal of intangible assets Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [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] Patents Patents [Member] Developed technology Developed Technology Rights [Member] Customer relationships—clients Customer Relationships, Venues And Promoters [Member] Customer Relationships, Venues And Promoters [Member] Customer relationships—users Customer Relationships, Users [Member] Customer Relationships, Users [Member] Trade names Trade Names [Member] Acquired Finite-Lived Intangible Assets [Line Items] Acquired Finite-Lived Intangible Assets [Line Items] Finite-lived intangible assets Finite-Lived Intangible Assets, Net [Abstract] Gross Carrying Amount Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Disposal of Intangible Assets Disposal Group, Including Discontinued Operation, Indefinite-Lived Intangible Assets Disposal Group, Including Discontinued Operation, Indefinite-Lived Intangible Assets Total intangible assets, Gross Carrying Amount Intangible Assets, Gross (Excluding Goodwill) Total intangible assets, Accumulated Amortization Total intangible assets Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Consolidation Consolidation, Policy [Policy Text Block] Reclassification Reclassification, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Stock-Based Compensation—Restricted Stock Units and Stock Options Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Net Loss per Common Share Earnings Per Share, Policy [Policy Text Block] Concentration of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Commitments and Contingencies Commitments and Contingencies, Policy [Policy Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Description of Business and Basis of Presentation Business Description and Basis of Presentation [Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Line of credit Line of Credit [Member] Letter of credit Letter of Credit [Member] Maximum borrowings available Line of Credit Facility, Maximum Borrowing Capacity Credit facility Proceeds from Lines of Credit Outstanding borrowings Long-term Debt, Gross Outstanding amount Letters of Credit Outstanding, Amount Available borrowing capacity Line of Credit Facility, Current Borrowing Capacity Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Quoted Prices in Active Markets for Identical Instruments (Level 1) Fair Value, Inputs, Level 1 [Member] Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [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: Assets, Fair Value Disclosure [Abstract] Total assets measured at fair value Assets, Fair Value Disclosure, Recurring Effective interest rate Receivable with Imputed Interest, Effective Yield (Interest Rate) Contractually stated interest income Interest Income, Contractual Amount Interest Income, Contractual Amount Effective interest rate Debt Instrument, Interest Rate, Effective Percentage Contractually stated interest expense Interest Expense, Debt, Excluding Amortization Amortization of discount Amortization of Debt Discount (Premium) Percentage of eligible compensation to purchase common stock through payroll deductions (as a percent) Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate Offering period Share-Based Compensation Arrangement By Share-Based Payment Award, Offering Period Represents the offering period for award under the share based compensation. Contributions from employees withheld Share Based Compensation Arrangement by Share Based Payment Award Contribution from Employees Withheld Represents the amount of contributions from employees withheld. Level 3 Fair Value, Inputs, Level 3 [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair value measured on a recurring basis Fair Value, Measurements, Recurring [Member] Total assets measured at fair value Liabilities measured at fair value Liabilities, Fair Value Disclosure, Recurring Fair value Alternative Investment, Fair Value Disclosure Redeemable Convertible Preferred Stock Stockholders' Equity Note Disclosure [Text Block] 1.75% convertible senior notes due 2020 Credit facility Long-term Line of Credit Unamortized discount and deferred issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Long-term debt, net Adjusted 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 Schedule of assumptions used for determining the per-share fair value of shares granted under the ESPP Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block] Schedule of stock-based compensation expenses related to all employee and non-employee stock-based awards Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Convertible Promissory Note Receivable Loans, Notes, Trade and Other Receivables Disclosure [Text Block]