Bank and government loans (Details Textual) $ in Thousands, ¥ in Millions				1 Months Ended		3 Months Ended
	May. 08, 2015	May. 13, 2014	May. 07, 2013	May. 22, 2012 USD ($)	May. 18, 2012 USD ($)	Mar. 31, 2015 USD ($)	Oct. 06, 2015	Sep. 30, 2015 USD ($)		Sep. 30, 2015 CNY (¥)	Mar. 31, 2015 CNY (¥)	Dec. 31, 2014 USD ($)		Dec. 31, 2014 CNY (¥)	Jul. 22, 2014 USD ($)	Jul. 22, 2014 CNY (¥)	Jul. 16, 2014 USD ($)	May. 22, 2012 CNY (¥)
Debt Instrument [Line Items]
Short-term Debt, Weighted Average Interest Rate								7.00%		7.00%		6.50%		6.50%
Non Revolving Credit Facility								$ 30,000				$ 30,000
Line of Credit Facility, Interest Rate at Period End								1.73%		1.73%
Time Deposits								$ 5,400		¥ 33.0		2,400		¥ 15.0
Industrial and Commercial Bank Of China Macau [Member]
Debt Instrument [Line Items]
Non Revolving Credit Facility				$ 30,000	$ 30,000
Line of Credit Facility, Description	LIBOR plus 1.40% per annum	LIBOR plus 2.55% per annum	LIBOR plus 2.0% per annum		LIBOR plus 2.25% per annum
Arrangement Fee				100
Line of Credit, Current				$ 31,600	$ 31,600
Line of Credit Facility, Expiration Date				May 22, 2013	Nov. 03, 2012
Industrial and Commercial Bank Of China Jingzhou Branch [Member]
Debt Instrument [Line Items]
Arrangement Fee				$ 100
HSBC Bank China Company Limited [Member]
Debt Instrument [Line Items]
Non Revolving Credit Facility															$ 5,000		$ 5,000
Line of Credit Facility, Interest Rate at Period End							1.50%										1.70%
Line of Credit, Current															5,400		$ 5,400
Time Deposits															$ 5,400	¥ 33.0
Line of Credit Facility, Expiration Date			Jul. 01, 2015
Chinese government loan [Member]
Debt Instrument [Line Items]
Short-term Debt, Total						$ 4,100		$ 3,930	[1]		¥ 25.0	$ 4,903	[1]
Debt Instrument, Interest Rate, Stated Percentage						2.50%					2.50%
Line of Credit Facility, Expiration Date						Apr. 20, 2016
Henglong [Member]
Debt Instrument [Line Items]
Financing Receivable, Net				$ 32,600														¥ 207.1
Short-term Debt, Total						$ 4,100					¥ 25.3

[1] On March 31, 2015, the Company received a Chinese government loan of RMB25.0 million, equivalent to approximately $4.1 million, with an interest rate of 2.5% per annum. The government loan will mature on April 20, 2016. Henglong pledged RMB25.3 million, equivalent to approximately $4.1 million, of notes receivable as security for such Chinese government loan (See Note 6).