Accounts Receivable, Net - Schedule of Accounts Receivable and Allowance for Doubtful Accounts (Detail) ¥ in Thousands, $ in Thousands |
Dec. 31, 2017
CNY (¥)
|
Dec. 31, 2017
USD ($)
|
Dec. 31, 2016
CNY (¥)
|
Dec. 31, 2016
USD ($)
|
Dec. 31, 2015
CNY (¥)
|
|---|---|---|---|---|---|
| Receivables [Abstract] | |||||
| Accounts receivable | ¥ 1,895,145 | $ 291,278 | ¥ 1,206,436 | ||
| Allowance for doubtful accounts | (1,408) | (216) | (512) | $ (79) | ¥ (2,315) |
| Total | ¥ 1,893,737 | $ 291,062 | ¥ 1,205,924 |