Segment and Geographic Information - Summary of Revenue and Long-Lived Assets, Net, by Geographic Area (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
Total Revenue	$ 39,625	$ 38,343
Long-Lived Assets, net
Total Long-Lived Assets, net	27,717	20,900
United States [Member]
Revenues:
Total Revenue	23,056	25,829
Long-Lived Assets, net
Total Long-Lived Assets, net	26,188	19,676
EMEA [Member]
Revenues:
Total Revenue	10,104	5,746
Long-Lived Assets, net
Total Long-Lived Assets, net	685	615
APAC [Member]
Revenues:
Total Revenue	4,786	5,053
Long-Lived Assets, net
Total Long-Lived Assets, net	254	158
Other [Member]
Revenues:
Total Revenue	1,679	1,715
Long-Lived Assets, net
Total Long-Lived Assets, net	$ 590	$ 451