Cash and Cash Equivalents - Summary of Time Deposits (Detail) In Thousands, unless otherwise specified	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2014 RMB [Member] USD ($)	Dec. 31, 2014 RMB [Member] CNY	Dec. 31, 2013 RMB [Member] USD ($)	Dec. 31, 2013 RMB [Member] CNY	Dec. 31, 2014 USD [Member] USD ($)	Dec. 31, 2014 USD [Member] CNY	Dec. 31, 2013 USD [Member] USD ($)	Dec. 31, 2013 USD [Member] CNY
Cash and Cash Equivalents [Line Items]
Time deposits	$ 31,117us-gaap_TimeDepositsAtCarryingValue	$ 30,892us-gaap_TimeDepositsAtCarryingValue	$ 25,617	156,749	$ 25,892	157,860	$ 5,500	5,500	$ 5,000	5,000

- Definition

Any certificate of deposit or savings account held by a bank or other financial institution for a short-term specified period of time. Because of their short-term, time deposits are considered highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

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