Bank short term debt - Summary of bank short term debt (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Debt Disclosure [Abstract]
Bank loan payable to Taiwan banks	$ 402,212	$ 413,351

Carrying value as of the balance sheet date of current portion of long-term loans payable to bank due within one year or the operating cycle if longer.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.20)

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20

-Article 5

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