Related Party Transactions - Summary of Related Parties Relationship with Group (Detail) |
12 Months Ended |
|---|---|
Dec. 31, 2017 | |
| Ping An Group [Member] | |
| Related Party Transaction [Line Items] | |
| Related parties relationship with the group | The Company's controlling shareholder and its subsidiaries |
| Hunan Mango Autohome Automobile Sales Co Ltd [Member] | |
| Related Party Transaction [Line Items] | |
| Related parties relationship with the group | An equity-method investee of the Company's subsidiary |