Summary of Company's debt (Detail) (USD $) In Thousands, unless otherwise specified			6 Months Ended		6 Months Ended		6 Months Ended		6 Months Ended		1 Months Ended		6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 US Term Note	Dec. 31, 2012 US Term Note	Jun. 30, 2013 Europe Term Note	Dec. 31, 2012 Europe Term Note	Jun. 30, 2013 W.E.T. Term Note	Dec. 31, 2012 W.E.T. Term Note	Jun. 30, 2013 Bank of China	Dec. 31, 2012 Bank of China	Jun. 30, 2013 DEG Loan	May 31, 2013 DEG Loan	Jun. 30, 2013 DEG Loan	Jun. 30, 2013 Capital Lease Obligations	Dec. 31, 2012 Capital Lease Obligations
Debt Instrument [Line Items]
Interest Rate			2.53%		2.51%		2.00%		6.90%		1.05%	0.231%	3.23%	4.20%
Total debt	$ 92,828	$ 56,952	$ 27,125	$ 29,312	$ 42,036	$ 4,476	$ 14,710	$ 18,852	$ 3,240	$ 3,172	$ 2,601		$ 2,601	$ 3,116	$ 1,140
Current portion	(22,598)	(17,218)
Long-term debt, less current maturities	$ 70,230	$ 39,734