Share-Based Compensation - Schedule of Share-Based Compensation Expenses (Detail) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014 USD ($)	Dec. 31, 2014 CNY	Dec. 31, 2013 CNY	Dec. 31, 2012 CNY	Dec. 31, 2014 Cost of Revenues [Member] USD ($)	Dec. 31, 2014 Cost of Revenues [Member] CNY	Dec. 31, 2013 Cost of Revenues [Member] CNY	Dec. 31, 2012 Cost of Revenues [Member] CNY	Dec. 31, 2014 Sales and Marketing Expenses [Member] USD ($)	Dec. 31, 2014 Sales and Marketing Expenses [Member] CNY	Dec. 31, 2013 Sales and Marketing Expenses [Member] CNY	Dec. 31, 2012 Sales and Marketing Expenses [Member] CNY	Dec. 31, 2014 General and Administrative Expenses [Member] USD ($)	Dec. 31, 2014 General and Administrative Expenses [Member] CNY	Dec. 31, 2013 General and Administrative Expenses [Member] CNY	Dec. 31, 2012 General and Administrative Expenses [Member] CNY	Dec. 31, 2014 Product Development Expenses [Member] USD ($)	Dec. 31, 2014 Product Development Expenses [Member] CNY	Dec. 31, 2013 Product Development Expenses [Member] CNY	Dec. 31, 2012 Product Development Expenses [Member] CNY
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 9,133	56,666	25,608	29,142	$ 1,298	8,048	6,534	6,553	$ 2,360	14,644	4,375	4,177	$ 3,313	20,557	11,738	15,734	$ 2,162	13,417	2,961	2,678

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.F)

-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)(i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration