Segment Information - Company's of Services Revenue (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue from External Customer [Line Items]
Total net services revenue	$ 177,657	$ 126,735	$ 89,711
Maintenance and Support [Member]
Revenue from External Customer [Line Items]
Total net services revenue	80,007	66,380	54,795
Professional Services and Training [Member]
Revenue from External Customer [Line Items]
Total net services revenue	13,693	14,084	11,414
Subscriptions [Member]
Revenue from External Customer [Line Items]
Total net services revenue	$ 83,957	$ 46,271	$ 23,502