Segment Reporting and Geographic Information (External Revenue and Long-Lived Assets by Geographic Region) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 38,385	$ 34,666	$ 115,465	$ 105,707
Long-Lived Assets	5,177		5,177		3,735
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	3,007		3,007		2,099
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	15,010	10,223	40,811	33,042
Americas (Excluding the U.S.)
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	972	1,638	3,452	4,702
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	21,276	17,234	66,565	60,140
Long-Lived Assets	2,132		2,132		1,590
Italy
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	16,046	13,911	51,529	49,517
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	1,127	5,571	4,637	7,823
Long-Lived Assets	$ 38		$ 38		$ 46