Cover [Abstract] Document Information [Table] Document Information [Line Items] Entity Registrant Name Document Registration Statement Document Annual Report Document Transition Report Document Shell Company Report Entity File Number Entity Central Index Key Document Type Entity Incorporation, State or Country Code Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Three Entity Address, City or Town Entity Address, Country Entity Address, Postal Zip Code Country Region City Area Code Local Phone Number Contact Personnel Fax Number Contact Personnel Name Title of 12(b) Security Entity Listing, Depository Receipt Ratio Entity Listing, Par Value Per Share Trading Symbol No Trading Symbol Flag Security Exchange Name Document Period End Date Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Emerging Growth Company Entity Common Stock, Shares Outstanding Entity Shell Company Document Accounting Standard Document Fiscal Year Focus Document Fiscal Period Focus Amendment Flag CONSOLIDATED BALANCE SHEETS Statement [Table] Related Party [Axis] Related Party [Domain] Related Party [Domain] Represents information pertaining to Alibaba Group Holding Limited, a strategic partner and significant shareholder of the Company. Alibaba Group Holding Limited [Member] Alibaba Counterparty Name [Axis] Repurchase Agreement Counterparty Name [Domain] Counterparty Name [Domain] Represents information pertaining to third parties. Third Parties [Member] Third parties Statement [Line Items] Statement Assets [Abstract] ASSETS Assets, Current [Abstract] Current assets: Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents at the end of the year Cash and cash equivalents at the beginning of the year Cash and cash equivalents Cash Short-term Investments Short-term investments Amount due from customers or clients and related parties, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Accounts Receivable Total Net Current Accounts receivable,net allowances for doubtful amounts Accounts receivable, net allowances for doubtful amounts Accounts receivable due from Alibaba Prepaid Expense and Other Assets, Current Prepaid expenses and other current assets (including loans to and interest receivables from other related parties of $43,695 and $301,526 as of December 31, 2018 and 2019, respectively) Prepaid expenses and other current assets Prepaid expenses and other current assets Short-Term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership. This does not include advances to clients. Advances to Affiliate, Current Amount due from SINA (Note 10) Amount due from SINA Assets, Current Total current assets Property, Plant and Equipment, Net Property and equipment, net Property and equipment, net Operating Lease, Right-of-Use Asset Right-of-use asset Operating lease assets Finite-Lived Intangible Assets, Net Intangible assets, net Intangible assets, net Goodwill Balance at the end of the year Balance at the beginning of the year Goodwill Long-term Investments. Balance at the end of year Balance at the beginning of the year Long-term investments Long-term Investments Other Assets, Noncurrent Other assets Assets Total assets Liabilities and Equity [Abstract] LIABILITIES AND SHAREHOLDERS' EQUITY Liabilities, Current [Abstract] Current liabilities (including amounts of the consolidated VIEs without recourse to the primary beneficiary of $347,770 and $436,705 as of December 31, 2018 and 2019, respectively.) Accounts Payable, Current Accounts payable Carrying value as of the balance sheet date of obligations incurred and payable, and liabilities classified as other, due within one year or within the normal operating cycle if longer. Accrued and Other Liabilities, Current Accrued and other liabilities Total accrued and other liabilities Operating Lease, Liability, Current Operating lease liability, short-term Accrued Income Taxes, Current Income taxes payable Contract with Customer, Liability, Current Deferred revenues Liabilities, Current Current liabilities Total current liabilities Current liabilities denominated in RMB Liabilities, Noncurrent [Abstract] Long-term liabilities Convertible Debt, Noncurrent Convertible debt Unsecured Long-term Debt, Noncurrent Unsecured senior notes Deferred Income Tax Liabilities, Net Deferred tax liability Operating Lease, Liability, Noncurrent Operating lease liability, long-term Liabilities, Noncurrent Total long-term liabilities Liabilities Total liabilities Commitments and Contingencies. Commitments and contingencies (Note 17) Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Shareholders' equity: Common Stock, Value, Issued Ordinary shares: $0.00025 par value; 2,400,000 and 2,400,000 shares (including 1,800,000 Class A ordinary shares, 200,000 Class B ordinary shares and 400,000 shares to be designated) authorized; 224,838 shares (including 123,059 Class A ordinary shares and 101,779 Class B ordinary shares) and 226,310 shares (including 124,531 Class A ordinary shares and 101,779 Class B ordinary shares) issued and outstanding as of December 31, 2018 and 2019, respectively. Additional Paid in Capital Additional paid-in capital Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss Retained Earnings (Accumulated Deficit) Retained earnings Stockholders' Equity Attributable to Parent Total Weibo shareholders' equity Stockholders' Equity Attributable to Noncontrolling Interest Non-controlling interests Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Balance Balance Total shareholders' equity Liabilities and Equity Total liabilities and shareholders' equity Allowance for Doubtful Accounts Receivable, Current Balance at the end of the year Balance at the beginning of the year Allowance for doubtful accounts Related Party Transaction, Due from (to) Related Party, Current Common Stock, Par or Stated Value Per Share Ordinary shares, par value (in dollars per share) Common Stock, Shares Authorized Ordinary shares, shares authorized Common Stock, Shares, Issued Balance (in shares) Balance (in shares) Ordinary shares, shares issued Common Stock, Shares, Outstanding Ordinary shares, shares outstanding CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Revenue Recognition [Abstract] Revenues: Revenue, Net Revenues Net revenues Cost of Goods and Services Sold [Abstract] Costs and Expenses Cost of Goods and Services Sold Cost of revenues Selling and Marketing Expense Sales and marketing Research and Development Expense Product development General and Administrative Expense General and administrative Goodwill and Intangible Asset Impairment Impairment Goodwill and acquired intangibles impairment Costs and Expenses Total costs and expenses Operating Income (Loss) Income from operations Income (Loss) from Equity Method Investments (Income) Loss from equity method investments Income (loss) from equity method investments Gain (Loss) from equity method investment Realized Investment Gains (Losses) Realized gain (loss) from investments Increase (Decrease) in Debt Securities, Trading, and Equity Securities, FV-NI Fair value changes through earnings on investment Fair value changes through earnings on investments, net Fair value change through earnings (including adjustment of subsequent price changes) Other than Temporary Impairment Losses, Investments Investment related impairment Impairment charge Investment related impairment Nonoperating Income (Expense) Interest and other income, net Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Income before income tax expenses Income before income tax expenses Income Tax Expense (Benefit) Income tax expense Income tax expenses Provision of income taxes Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income Net income Net income (loss) Net Income (Loss) Attributable to Noncontrolling Interest Less: Net income (loss) attributable to non-controlling interests Net Income (Loss) Attributable to Parent Net income attributable to Weibo Net income attributable to Weibo Net income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other comprehensive income (loss) Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Currency translation adjustments (net of tax of nil, nil, and nil for 2017, 2018 and 2019, respectively) Currency translation adjustments Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Abstract] Available-for-Sale securities Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Change in unrealized loss from available-for-sale securities (net of tax of nil, nil, and nil for 2017, 2018, and 2019, respectively) Unrealized loss on accumulated other comprehensive income to retained earnings Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Less: Comprehensive income (loss) attributable to non-controlling interests Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive income attributable to Weibo Weighted Average Number of Shares Outstanding, Diluted [Abstract] Shares used in computing net income per share attributable to Weibo: Denominator: Weighted Average Number of Shares Outstanding, Basic Basic (in shares) Weighted average ordinary shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Diluted (in shares) Shares used in computing diluted net income per share attributable to Weibo (in shares) Earnings Per Share, Basic and Diluted [Abstract] Income per share: Earnings Per Share, Basic Basic (in dollars per share) Basic net income per share attributable to Weibo (in dollars per share) Earnings Per Share, Diluted Diluted (in dollars per share) Diluted net income per share attributable to Weibo (in dollars per share) Other Comprehensive Income (Loss), Foreign Currency Translation Gain (Loss) Arising During Period, Tax Currency translation adjustments, tax Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax Change in unrealized loss from available-for-sale securities, tax CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Shareholders' Equity Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Issuance of ordinary shares pursuant to stock plan Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Issuance of ordinary shares pursuant to stock plan (in shares) Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Non-cash stock-based compensation Cumulative Effect of New Accounting Principle in Period of Adoption Impact of adoption of new accounting guidance (Note 2) Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Unrealized loss from available-for-sale securities Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Purchase of subsidiaries' shares from non-controlling shareholders CONSOLIDATED STATEMENTS OF CASH FLOWS Net Cash Provided by (Used in) Operating Activities [Abstract] Cash flows from operating activities: Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Depreciation, Depletion and Amortization, Nonproduction Depreciation and amortization Share-based Compensation Stock-based compensation Amount of amortization expense attributable to right-of-use asset from operating lease. Operating Lease, Right-of-Use Asset, Amortization Amortization of operating lease - right of use assets Provision for Doubtful Accounts Additional provision charged to expenses, net Provision for allowance for doubtful accounts Deferred Income Taxes and Tax Credits Deferred income taxes Proceeds from Equity Method Investment, Distribution Dividend received from equity method investment Dividend received from equity method investments Gain (Loss) on Sale of Investments (Gain) Loss on sale of investments Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Gain on disposal of property and equipment Amortization of Debt Issuance Costs Amortization of convertible debt and unsecured senior notes issuance cost Increase (Decrease) in Operating Capital [Abstract] Changes in assets and liabilities, net of acquisition: Increase (Decrease) in Accounts Receivable Accounts receivable due Increase (Decrease) in Prepaid Expense and Other Assets Prepaid expenses and other current assets Increase (Decrease) in Other Noncurrent Assets Other assets Increase (Decrease) in Accounts Payable Accounts payable The increase (decrease) during the reporting period in the aggregate amount of expenses and other liabilities incurred but not yet paid. Increase (Decrease) in Accrued and Other Liabilities Accrued and other liabilities The aggregate increase (decrease) during the reporting period in the amount due from the following types of related parties: a parent company and its subsidiaries; subsidiaries of a common parent; an entity and trust for the benefit of employees, such as pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; an entity and its principal owners, management, or member of their immediate families, affiliates, or other parties with the ability to exert significant influence. Increase (Decrease) in Due from and Due to Related Parties, Current Amount due to (from) SINA ncrease (Decrease) in Contract with Customer, Liability Deferred revenues The increase (decrease) during the reporting period in operating lease liabilities. Increase (Decrease) In Operating Lease Liabilities Operating lease liabilities Increase (Decrease) in Income Taxes Payable Income taxes payable Net Cash Provided by (Used in) Operating Activities Net cash provided by (used in) operating activities Net cash provided by operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from investing activities: Payments to Acquire Short-term Investments Purchases of short-term investments Proceeds from Maturities, Prepayments and Calls of Short-term Investments Maturities of short-term investments Payments to Acquire Long-term Investments Cash paid (including prepayment) on long-term investments Proceeds from Sale, Maturity and Collection of Long-term Investments Proceeds from disposal of/refund of prepayment on long-term investments Proceeds from Sale of Property, Plant, and Equipment Proceeds from disposal of property and equipment Payments to Acquire Property, Plant, and Equipment Purchases of property and equipment The cash outflow from the loans provided. Loans Provided Classified as Investing Activities Loan to SINA Loan to SINA Proceeds from Collection of Loans Receivable Repayment of loan by SINA Loan repaid by SINA Payments to Acquire Businesses, Net of Cash Acquired Cash paid for business acquisition, net of cash acquired Net Cash Provided by (Used in) Investing Activities Net cash used in investing activities Net cash used in investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities: Proceeds from Stock Options Exercised Proceeds from employee options exercised Cash received from the exercise of stock option Proceeds from Convertible Debt Proceeds from convertible notes, net of debt issuance costs Net proceeds from issuance of the Notes Proceeds from Unsecured Notes Payable Proceeds from unsecured senior notes, net of debt issuance costs Proceeds from Related Party Debt Loan from SINA Principal and interest income of loan to SINA's subsidiary Repayments of Related Party Debt Repayment of loan from SINA Principal and interest expense of loan from SINA Payments to Noncontrolling Interests Payments to non-controlling shareholders Net Cash Provided by (Used in) Financing Activities Net cash provided by financing activities Net cash provided by (used in) financing activities Effect of Exchange Rate on Cash and Cash Equivalents Effect of exchange rate changes on cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Net increase in cash and cash equivalents Supplemental Cash Flow Information [Abstract] Supplemental disclosure of cash flow information Interest Paid, Net Cash paid for interest expenses Income Taxes Paid, Net Cash paid for income tax Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Supplemental schedule of non-cash investing and financing activities Capital Expenditures Incurred but Not yet Paid Property and equipment in accounts payable Noncash or Part Noncash Acquisition, Net Nonmonetary Assets Acquired (Liabilities Assumed) Unpaid consideration for acquisitions Amount of consideration settled for acquisition of a business or asset in a noncash transaction. Noncash Or Part Noncash Acquisition, Consideration Settled Consideration settled for acquisition (Note 10) Operations Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Operations Significant Accounting Policies