Basis of Presentation and Summary of Significant Accounting Policies - Summary of Revenue Comprised of Major Product and Service Lines (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation Of Revenue [Line Items]
Total net revenue	$ 84,800	$ 74,435	$ 169,044	$ 146,743
Products and Licenses [Member]
Disaggregation Of Revenue [Line Items]
Total net revenue	19,218	20,012	39,730	39,590
Subscriptions [Member]
Disaggregation Of Revenue [Line Items]
Total net revenue	36,484	28,097	71,438	55,349
Maintenance and Support [Member]
Disaggregation Of Revenue [Line Items]
Total net revenue	24,948	22,596	50,173	44,576
Professional Services and Training [Member]
Disaggregation Of Revenue [Line Items]
Total net revenue	4,150	3,730	7,703	7,228
Total Services [Member]
Disaggregation Of Revenue [Line Items]
Total net revenue	$ 65,582	$ 54,423	$ 129,314	$ 107,153