Segment Information (Revenues Attributable to Domestic and Foreign Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Segment Reporting Information [Line Items]
Revenue	$ 51,087		$ 43,229		$ 98,915		$ 85,725
United States [Member]
Segment Reporting Information [Line Items]
Revenue	33,765		28,966		64,865		57,606
Other Americas [Member]
Segment Reporting Information [Line Items]
Revenue	2,172	[1]	1,825	[1]	4,321	[1]	3,792	[1]
Americas [Member]
Segment Reporting Information [Line Items]
Revenue	35,937		30,791		69,186		61,398
EMEA [Member]
Segment Reporting Information [Line Items]
Revenue	11,055	[2]	8,051	[2]	21,569	[2]	15,972	[2]
APAC [Member]
Segment Reporting Information [Line Items]
Revenue	$ 4,095	[3]	$ 4,387	[3]	$ 8,160	[3]	$ 8,355	[3]

[1] Canada, Latin America and South America

[2] Europe, the Middle East and Africa (“EMEA”)

[3] Asia-Pacific (“APAC”)