Segment Information (Revenues Attributable to Domestic and Foreign Operations) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Revenue		$ 60,757	$ 52,787	$ 179,861	$ 151,702
United States [Member]
Segment Reporting Information [Line Items]
Revenue		39,972	34,409	120,409	99,273
Other Americas [Member]
Segment Reporting Information [Line Items]
Revenue	[1]	3,589	2,936	9,437	7,259
Americas [Member]
Segment Reporting Information [Line Items]
Revenue		43,561	37,345	129,846	106,532
EMEA [Member]
Segment Reporting Information [Line Items]
Revenue	[2]	13,237	11,049	38,443	32,618
APAC [Member]
Segment Reporting Information [Line Items]
Revenue	[3]	$ 3,959	$ 4,393	$ 11,572	$ 12,552

[1] Canada, Latin America and South America

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

[3] Asia-Pacific (“APAC”)