Notes payable - Additional Information (Detail) ¥ in Millions, $ in Millions |
6 Months Ended | |||||
|---|---|---|---|---|---|---|
|
Jun. 30, 2026
CNY (¥)
|
Jun. 30, 2025
CNY (¥)
|
Jun. 30, 2026
USD ($)
|
Dec. 31, 2025
CNY (¥)
|
Dec. 31, 2025
USD ($)
|
Sep. 30, 2020
USD ($)
|
|
| Disclosure of Detailed Information Unsecured Senior Notes [Line Items] | ||||||
| Aggregate principal | ¥ 3,390 | ¥ 3,497 | ||||
| Fair values of notes payable | 3,066 | $ 450 | ¥ 3,176 | $ 452 | ||
| Interest paid for notes payable | ¥ 35 | ¥ 51 | ||||
| Senior Unsecured Notes | ||||||
| Disclosure of Detailed Information Unsecured Senior Notes [Line Items] | ||||||
| Aggregate principal | $ | $ 800 | |||||