Commitments and Contingencies - Additional Information (Detail) ¥ in Thousands, $ in Thousands |
12 Months Ended | ||||
|---|---|---|---|---|---|
|
Dec. 31, 2017
CNY (¥)
|
Dec. 31, 2017
USD ($)
|
Dec. 31, 2016
CNY (¥)
|
Dec. 31, 2015
CNY (¥)
|
Dec. 31, 2017
USD ($)
|
|
| Disclosure of commitments and contingencies [Line Items] | |||||
| Minimum operating lease payments recognized as an expense | ¥ 54,671 | $ 8,638 | ¥ 54,617 | ¥ 60,201 | |
| Capital commitments related to property, plant and equipment | 409,487 | 427,089 | $ 64,696 | ||
| Investments commitments related to interest in joint venture | 0 | 75,000 | 0 | ||
| Irrevocable letter of credits issued | ¥ 1,905 | ¥ 29,729 | $ 301 | ||
| Bottom of range [Member] | |||||
| Disclosure of commitments and contingencies [Line Items] | |||||
| Property plant and equipment, subject to or available for operating lease useful life average | 1 year | 1 year | |||
| Top of range [Member] | |||||
| Disclosure of commitments and contingencies [Line Items] | |||||
| Property plant and equipment, subject to or available for operating lease useful life average | 5 years | 5 years | |||