Segment Information (Revenues Attributable to Domestic and Foreign Operations) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Revenue		$ 56,679	$ 59,334	$ 112,144	$ 119,104
United States [Member]
Segment Reporting Information [Line Items]
Revenue		38,272	38,996	76,063	80,437
Other Americas [Member]
Segment Reporting Information [Line Items]
Revenue	[1]	1,546	3,145	3,092	5,848
Americas [Member]
Segment Reporting Information [Line Items]
Revenue		39,818	42,141	79,155	86,285
EMEA [Member]
Segment Reporting Information [Line Items]
Revenue	[2]	12,274	13,421	23,880	25,206
APAC [Member]
Segment Reporting Information [Line Items]
Revenue	[3]	$ 4,587	$ 3,772	$ 9,109	$ 7,613

[1] Canada, Latin America and South America

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

[3] Asia-Pacific (“APAC”)