Segment Reporting and Geographic Information (External Revenue and Long-Lived Assets by Geographic Region) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 42,318	$ 38,905
Long-Lived Assets	5,391		5,555
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	3,239		3,326
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	12,856	12,125
Americas (Excluding the U.S.)
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	556	1,625
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	26,579	23,421
Long-Lived Assets	2,119		2,194
Italy
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	20,400	18,100
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	2,327	1,734
Long-Lived Assets	$ 33		$ 35