Debt - Additional Information (Detail)	12 Months Ended				12 Months Ended										1 Months Ended	12 Months Ended
	Dec. 31, 2013 USD ($)	Dec. 31, 2013 EUR (€)	Dec. 31, 2012 USD ($)	Dec. 31, 2012 EUR (€)	Dec. 31, 2013 Federal Funds Rate Minimum	Dec. 31, 2013 Federal Funds Rate Maximum	Dec. 31, 2013 US Bank of America credit facility Maximum	Dec. 31, 2013 W.E.T. Bank of America credit facility Minimum	Dec. 31, 2013 Eurocurrency Rate Loans	Dec. 31, 2013 Eurocurrency Rate Loans Minimum	Dec. 31, 2013 Eurocurrency Rate Loans Maximum	Dec. 31, 2013 Base Rate Loans	Dec. 31, 2013 German Investment Corporation USD ($)	Dec. 31, 2013 German Investment Corporation EUR (€)	Mar. 31, 2011 Europe Term Note USD ($)	Dec. 31, 2013 Europe Term Note	Dec. 31, 2012 Europe Term Note
Debt Disclosure [Line Items]
Debt instrument, description	The Company has the option to elect interest rates based on either a Eurocurrency (LIBOR or EUIBOR) rate (“Eurocurrency Rate Loans”) (0.16% – 0.48% at December 31, 2013) or a base rate (“Base Rate Loans”) plus a margin (“Applicable Rate”), which varies based on the Consolidated Leverage Ratio of the Company, as defined by the US and W.E.T. Bank of America credit agreements.	The Company has the option to elect interest rates based on either a Eurocurrency (LIBOR or EUIBOR) rate (“Eurocurrency Rate Loans”) (0.16% – 0.48% at December 31, 2013) or a base rate (“Base Rate Loans”) plus a margin (“Applicable Rate”), which varies based on the Consolidated Leverage Ratio of the Company, as defined by the US and W.E.T. Bank of America credit agreements.
Interest rate					0.07%	0.50%	3.25%	1.00%	2.25%	0.16%	0.48%	1.25%				2.49%	1.80%
Line of credit available amount	$ 29,550,000	€ 20,000,000	$ 29,550,000	€ 20,000,000
Outstanding letter of credit	450,000		450,000
Debt instrument face amount													5,561,000	4,000,000
Fixed interest rate													4.25%	4.25%
Additional Borrowings															$ 40,400,000