Breakdown of Expiration of Net Operating Loss Carryforwards in Major Jurisdictions (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
Amount	$ 13,507
Hong Kong
Operating Loss Carryforwards [Line Items]
Amount	9,174
Expiring year	Indefinite
Taiwan
Operating Loss Carryforwards [Line Items]
Amount	$ 4,333
Expiring year	2021

The sum of domestic, foreign and state and local operating loss carryforwards, before tax effects, available to reduce future taxable income under enacted tax laws.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 48

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_OperatingLossCarryforwards
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant