Bank and government loans- net (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013		Dec. 31, 2012
Short-term government loan	$ 6,380	[1]	$ 0	[1]
Subtotal	46,953		40,341
Debt issue cost	(230)		(230)
Amortization	211		173
Bank and government loans	46,934		40,284
Usd [Member]
Short-term bank loan	10,573	[2],[3]	10,341	[2],[3]
Rmb [Member]
Short-term bank loan	$ 30,000	[4]	$ 30,000	[4]

[1] On January 31, 2013, the Company received an interest-free Chinese government loan of RMB40.0 million (equivalent to approximately $6.4 million), which will mature in a year. Henglong has pledged RMB40.0 million (equivalent to approximately $6.4 million) of notes receivable, which will mature on December 31, 2013, as security for the purpose of obtaining a RMB40.0 million (equivalent to approximately $6.4 million) interest-free loan from the Chinese government.

[2] These loans are secured by property, plant and equipment of the Company and are repayable within one year. Please see Note 8. At March 31, 2013 and December 31, 2012, the weighted average interest rate was 5.98% and 6.46% per annum, respectively. Interest is to be paid on the twentieth day of each month and the principal repayment is at maturity.

[3] On June 30, 2012, Jiulong entered in to a one-year loan agreement with China Construction Bank Jingzhou branch in the amount of $3.2 million. The agreement contains certain financial and non-financial covenants, including but not limited to restrictions on the utilization of the funds and the maintenance of an asset-liability ratio not exceeding 60%. The Company was in compliance with these covenants as of March 31, 2013.

[4] On May 18, 2012, the Company entered into a credit facility agreement, the "Credit Agreement," with ICBC Macau to obtain a non-revolving credit facility in the amount of $30 million, the "Credit Facility". The Credit Facility would have expired on November 3, 2012 unless the Company drew down the line of credit in full prior to such expiration date, and the maturity date for the loan drawdown was the earlier of (i) 18 months from the drawdown or (ii) 1 month before the expiry of the standby letter of credit obtained by Henglong from ICBC Jingzhou as security for the Credit Facility, the "Henglong Standby Letter of Credit". The interest rate of the Credit Facility is calculated based on a three-month LIBOR plus 2.25% per annum, subject to the availability of funds and fluctuation at ICBC Macau's discretion. The interest is calculated daily based on a 360-day year and it is to be fixed one day before the first day of each interest period. The interest period is defined as three months from the date of drawdown. As of March 31, 2013, the interest rate was 2.62% per annum. As security for the Credit Facility, the Company was required to provide ICBC Macau with the Henglong Standby Letter of Credit for a total amount not less than $31.6 million if the Credit Facility is fully drawn. On May 22, 2012, the Company drew down the full amount of $30.0 million under the Credit Facility and provided the Henglong Standby Letter of Credit for an amount of $31.6 million in favor of ICBC Macau. The loan drawdown will expire on May 15, 2013. The Henglong Standby Letter of Credit issued by ICBC Jingzhou with the collateralization of Henglong's notes receivable of RMB240 million (equivalent to approximately $38.2 million) will expire on June 15, 2013. The Company also paid an arrangement fee of $0.1 million to ICBC Macau and $0.1 million to ICBC Jingzhou. The arrangement fees are amortized over the period of loan drawdown, and $0.04 million was amortized for the three months ended March 31, 2013.