Notes payable - Summary of Note Payable (Detail) - CNY (¥) ¥ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Disclosure of detailed information about borrowings [line items] | ||
| Included in non-current liabilities | ¥ 3,390 | ¥ 3,497 |
| Non-current liabilities [Member] | ||
| Disclosure of detailed information about borrowings [line items] | ||
| Included in non-current liabilities | ¥ 3,390 | ¥ 3,497 |