Prepayment on property, plant and equipment (Details) (USD $)	1 Months Ended
Apr. 30, 2012	Dec. 31, 2012	Oct. 26, 2012 sqm	Dec. 31, 2011
Prepayment on property, plant and equipment (Textual)
Prepayment on property, plant and equipment		$ 1,445,645		$ 7,241,472
Entitlement of land use rights			54,267
Prepayment of the land use rights reclassified as land use rights under property, plant and equipment	$ 7,241,472

Carrying amount as of the balance sheet date of amounts paid in advance which will be charged against earnings in periods after one year or beyond 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 210.5-02.17)

-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 17

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 4

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=6361293&loc=d3e6812-107765

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