Summary of Significant Accounting Policies - Schedule of Balances of Registered Capital, Additional Paid-in-Capital and Statutory Reserves (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies and General Information [Line Items]
Additional paid-in capital	$ 446,202us-gaap_AdditionalPaidInCapital	$ 61,634us-gaap_AdditionalPaidInCapital
Statutory reserves	5,132xnet_StatutoryReserve	4,478xnet_StatutoryReserve
China [Member]
Accounting Policies and General Information [Line Items]
Registered capital	54,467	44,532
Additional paid-in capital	161	161
Statutory reserves	5,132	4,478
Total	$ 59,760	$ 49,171

Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.30(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_AdditionalPaidInCapital
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant