Principal Accounting Policies - Operating leases and Adoption of ASU (Details) - CNY (¥) ¥ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Accounting Policies [Abstract] | |||
| Operating lease weighted average remaining lease term | 4 years 5 months 4 days | ||
| Operating lease, weighted average discount rate | 4.03% | ||
| Operating lease cost and expenses | ¥ 18.4 | ¥ 23.8 | ¥ 25.4 |
| Short term lease cost and expenses | ¥ 1.3 | ¥ 1.3 | ¥ 1.4 |