Segment Information (Revenues Attributable to Domestic and Foreign Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Revenue	$ 47,828	$ 42,496
United States [Member]
Segment Reporting Information [Line Items]
Revenue	31,098	28,639
Other Americas [Member]
Segment Reporting Information [Line Items]
Revenue	2,150	1,967
Americas [Member]
Segment Reporting Information [Line Items]
Revenue	33,248	30,606
EMEA [Member]
Segment Reporting Information [Line Items]
Revenue	10,515	7,921
APAC [Member]
Segment Reporting Information [Line Items]
Revenue	$ 4,065	$ 3,969