Basis of Presentation and Summary of Significant Accounting Policies - Summary of Impacts of Adopting the New Standard on Statement of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net revenue:
Products and license	$ 20,512	$ 19,578
Services:
Subscriptions	34,953
Maintenance and Support	25,226
Professional services and training	3,553
Total services	63,732	52,730
Total net revenue	84,244	72,308
Operating expenses:
Sales and marketing	39,531	37,124
Loss from operations	(11,237)	(11,738)
Net (loss) income	$ (9,781)	$ 23,083
Net loss per share of common stock stockholders, basic and diluted	$ (0.28)
Adjustments [Member] | Topic 606 [Member]
Net revenue:
Products and license	$ (234)
Services:
Subscriptions	86
Maintenance and Support	(958)
Professional services and training	62
Total services	(810)
Total net revenue	(1,044)
Operating expenses:
Sales and marketing	2,585
Loss from operations	(3,629)
Net (loss) income	$ (3,629)
Net loss per share of common stock stockholders, basic and diluted	$ (0.11)
Balances Without Adoption of Topic 606 [Member] | Topic 606 [Member]
Net revenue:
Products and license	$ 20,278
Services:
Subscriptions	35,039
Maintenance and Support	24,268
Professional services and training	3,615
Total services	62,922
Total net revenue	83,200
Operating expenses:
Sales and marketing	42,116
Loss from operations	(14,866)
Net (loss) income	$ (13,410)
Net loss per share of common stock stockholders, basic and diluted	$ (0.39)