Summary of Company's debt (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Total debt	$ 91,823	$ 56,952
Current portion	(22,509)	(17,218)
Long-term debt, less current maturities	69,314	39,734
US Term Note
Debt Instrument [Line Items]
Interest Rate	2.02%
Total debt	28,219	29,312
Europe Term Note
Debt Instrument [Line Items]
Interest Rate	2.01%
Total debt	43,367	4,476
W.E.T. Term Note
Debt Instrument [Line Items]
Interest Rate	2.00%
Total debt	16,603	18,852
Bank Of China
Debt Instrument [Line Items]
Interest Rate	6.90%
Total debt	3,191	3,172
Capital Lease Obligations
Debt Instrument [Line Items]
Interest Rate	5.50%
Total debt	$ 443	$ 1,140