Segment Information - Components of Net Services Revenue (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net services revenue	$ 19,545	$ 14,431
Maintenance and support [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net services revenue	12,663	10,114
Professional services and training [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net services revenue	2,299	2,275
Subscriptions [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net services revenue	$ 4,583	$ 2,042