Segment Information - Company's of Services Revenue (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue from External Customer [Line Items]
Total net services revenue	$ 126,735	$ 89,711	$ 65,606
Maintenance and Support [Member]
Revenue from External Customer [Line Items]
Total net services revenue	66,380	54,795	44,353
Professional Services and Training [Member]
Revenue from External Customer [Line Items]
Total net services revenue	14,084	11,414	9,890
Subscriptions [Member]
Revenue from External Customer [Line Items]
Total net services revenue	$ 46,271	$ 23,502	$ 11,363