Accounts Receivable, 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 (¥)
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||
| Additions to allowance for doubtful accounts | ¥ 1,110 | $ 170 | ¥ 2,303 | ¥ 2,179 |
| General and Administrative Expenses [Member] | ||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||
| Additions to allowance for doubtful accounts | ¥ 1,110 | $ 170 | ¥ 2,303 | ¥ 2,179 |