Related Party Transactions - Summary of Related Parties Relationship with Group (Detail)	12 Months Ended
Dec. 31, 2014
Telstra International HK Limited [Member]
Related Party Transaction [Line Items]
Related parties relationship with the group	A wholly-owned subsidiary of the Company's major shareholder
Telstra International Limited [Member]
Related Party Transaction [Line Items]
Related parties relationship with the group	A wholly-owned subsidiary of the Company's major shareholder
Beijing Australian Telecommunications Technical Consulting Limited [Member]
Related Party Transaction [Line Items]
Related parties relationship with the group	A wholly-owned subsidiary of the Company's major shareholder

This element represents a description of the nature of common ownership or management control relationships with other entities, regardless of there being transactions between the entities, when the existence of that control could result in operating results or financial position of the reporting entity significantly different from that which would have been obtained if the entities' were autonomous.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39691-107864

Name:	us-gaap_NatureOfCommonOwnershipOrManagementControlRelationships
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration