Related Party Transactions (Details) - USD ($)
1 Months Ended 12 Months Ended
Dec. 31, 2021
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Related party transactions        
Costs and expenses allocated from SINA(1)   $ 38,270,000 $ 43,011,000 $ 51,848,000
Total revenues   70,000,000.0 46,500,000 117,000,000.0
Related party outstanding balance:        
Amount due from SINA $ 494,200,000 494,200,000 548,900,000  
Loans to and interest receivable 219,679,000 219,679,000 158,622,000  
Loans to and interest receivable 480,786,000 480,786,000 0  
Total 700,465,000 700,465,000 158,622,000  
Impairment charges on loans to and interest receivable from other related parties   0 82,200,000  
Advertising and marketing revenues from related party   70,000,000.0 46,500,000 117,000,000.0
Other revenues generated from related parties   3,300,000 3,400,000 5,400,000
Cost and expenses recognized from transactions with other related parties   62,600,000 48,100,000 $ 31,200,000
Accounts receivable due from other related parties 55,800,000 55,800,000 42,500,000  
Accounts payable due to other related parties 44,300,000 44,300,000 30,800,000  
Accrued and other liabilities due to other related parties 8,300,000 $ 8,300,000 $ 4,800,000  
SINA        
Related party transactions        
Loan agreement term   1 year 1 year 1 year
Loan to SINA   $ 978,162,000 $ 473,777,000 $ 233,884,000
Loan repaid by SINA   1,058,574,000 181,697,000 43,567,000
Revenue billed through SINA   68,351,000 41,754,000 109,949,000
Revenue from services provided to SINA   43,170,000 20,348,000 27,274,000
Costs and expenses allocated from SINA(1)   38,270,000 43,011,000 51,848,000
Interest income on loans to SINA   17,943,000 13,458,000 9,295,000
Total revenues   111,521,000 62,102,000 137,223,000
Other costs and expenses billed by SINA   48,000,000.0 48,300,000 37,500,000
Costs and expenses paid by Weibo on behalf of SINA and allocated   800,000 9,700,000  
Related party outstanding balance:        
Amount due from SINA 494,200,000 494,200,000 548,900,000  
Loans to and interest receivable 479,600,000 479,600,000 547,900,000  
Advertising and marketing revenues from related party   111,521,000 62,102,000 137,223,000
Alibaba        
Related party transactions        
Services provided by Alibaba   44,006,000 52,338,000 50,205,000
Related party outstanding balance:        
Accounts receivable due from related parties 89,344,000 89,344,000 135,321,000  
Alibaba | Advertiser        
Related party transactions        
Total revenues   139,561,000 152,000,000 97,772,000
Related party outstanding balance:        
Accounts receivable due from related parties 89,344,000 89,344,000 135,321,000  
Advertising and marketing revenues from related party   139,561,000 152,000,000 97,772,000
Alibaba | Agent        
Related party transactions        
Total revenues   41,680,000 36,597,000 0
Related party outstanding balance:        
Advertising and marketing revenues from related party   41,680,000 36,597,000 0
Company A        
Related party outstanding balance:        
Loans to and interest receivable 0 0 79,762,000  
Company B        
Related party outstanding balance:        
Loans to and interest receivable 2,789,000 2,789,000 21,771,000  
Company C        
Related party outstanding balance:        
Loans to and interest receivable 211,583,000 211,583,000 41,205,000  
Company D        
Related party outstanding balance:        
Loans to and interest receivable 480,786,000 480,786,000 0  
Company D | Other non-current assets        
Related party outstanding balance:        
Loans to and interest receivable 480,786,000 480,786,000 0  
Subtotal | Prepaid expenses and other current assets        
Related party outstanding balance:        
Loans to and interest receivable 219,679,000 219,679,000 158,622,000  
Other related parties        
Related party outstanding balance:        
Accounts receivable due from related parties 55,763,000 55,763,000 42,530,000  
Loans to and interest receivable $ 5,307,000 $ 5,307,000 15,884,000  
Minimum | SINA        
Related party outstanding balance:        
Annual interest rate   1.00%    
Minimum | Company B        
Related party outstanding balance:        
Annual interest rate 4.00%      
Maximum | SINA        
Related party outstanding balance:        
Annual interest rate   4.50%    
Maximum | Company B        
Related party outstanding balance:        
Annual interest rate 10.00%      
Advertising & Marketing | SINA        
Related party transactions        
Total revenues   $ 96,359,000 48,353,000 112,974,000
Related party outstanding balance:        
Advertising and marketing revenues from related party   96,359,000 48,353,000 112,974,000
Value-added services | SINA        
Related party transactions        
Total revenues   15,162,000 13,749,000 24,249,000
Related party outstanding balance:        
Advertising and marketing revenues from related party   $ 15,162,000 $ 13,749,000 $ 24,249,000