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, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 50,736	$ 38,385	$ 38,175	$ 38,905	$ 45,954	$ 34,666	$ 37,626	$ 33,415	$ 166,201	$ 151,661	$ 157,068
Long-Lived Assets	5,555				3,735				5,555	3,735
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									55,071	47,250	51,076
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									4,200	6,008	6,357
Long-Lived Assets	3,326				2,099				3,326	2,099
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									98,843	88,868	94,317
Long-Lived Assets	2,194				1,590				2,194	1,590
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									8,087	9,521	5,296
Long-Lived Assets	35				46				35	46
Other regions
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									0	14	22
ITALY
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 76,600	$ 73,100	$ 77,000