Revenue from Contracts with Customers - Disaggregation of Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Total revenue	$ 343,899	$ 289,418	$ 1,029,664	$ 878,204
Lease licenses
Disaggregation of Revenue [Line Items]
Total revenue	70,693	43,202	239,953	148,795
Perpetual licenses
Disaggregation of Revenue [Line Items]
Total revenue	66,451	65,901	190,734	201,501
Software licenses
Disaggregation of Revenue [Line Items]
Total revenue	137,144	109,103	430,687	350,296
Maintenance
Disaggregation of Revenue [Line Items]
Total revenue	193,189	171,463	559,768	500,962
Service
Disaggregation of Revenue [Line Items]
Total revenue	13,566	8,852	39,209	26,946
Maintenance and service
Disaggregation of Revenue [Line Items]
Total revenue	$ 206,755	$ 180,315	$ 598,977	$ 527,908
Direct revenue, as a percentage of total revenue
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	76.80%	75.50%	75.90%	76.10%
Indirect revenue, as a percentage of total revenue
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	23.20%	24.50%	24.10%	23.90%