Principal Accounting Policies - Summary of Concentration Risk (Details) - Customer Concentration Risk - Accounts Receivable |
12 Months Ended | |
|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
|
| Customer A Social Media Platform [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, percentage | 12.00% | |
| Customer B Education Media Platform [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, percentage | 16.00% | |