Notes Payable-Banks (Details Textual) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013 EUR (€)	Jun. 30, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2012 EUR (€)	Jun. 30, 2011 USD ($)	Apr. 28, 2011 USD ($)
Line of Credit Facility, Maximum Borrowing Capacity	€ 3,730	$ 4,853	$ 5,845	€ 4,430
Line of Credit Facility, Interest Rate at Period End		0.21%
Line of Credit Facility, Amount Outstanding		59,111	33,534			200,000
Revolving Line Of Credit Facility					175,000
Additional Line Of Credit Facility						50,000
Line Of Credit Facility, Amount Utilized		168,111	151,784
Line of Credit Facility, Commitment Fee Amount	€ 8,000
Line Of Credit Facility, Interest Rate, Variable Rate Basis	EURIBOR plus 1.75%