Segment Reporting and Geographic Information (External Revenue and Long-Lived Assets by Geographic Region) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 43,444	$ 43,170	$ 43,124	$ 42,318	$ 50,736	$ 38,385	$ 38,175	$ 38,905	$ 172,056	$ 166,201	$ 151,661
Long-Lived Assets	4,890				5,555				4,890	5,555
Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	3,078				3,326				3,078	3,326
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									51,036	55,071	47,250
Americas (Excluding the U.S.) [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									1,507	4,200	6,008
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									105,996	98,843	88,868
Long-Lived Assets	1,786				2,194				1,786	2,194
Italy [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									86,300	76,600	73,100
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									13,517	8,087	9,521
Long-Lived Assets	26				35				26	35
Other Regions [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 0	$ 0	$ 14