Property and Equipment, Net - Additional Information (Detail) ¥ in Thousands, $ in Thousands |
12 Months Ended | |||
|---|---|---|---|---|
|
Dec. 31, 2017
CNY (¥)
|
Dec. 31, 2017
USD ($)
|
Dec. 31, 2016
CNY (¥)
|
Dec. 31, 2015
CNY (¥)
|
|
| Property, Plant and Equipment [Abstract] | ||||
| Depreciation expense | ¥ 81,915 | $ 12,590 | ¥ 65,246 | ¥ 51,337 |