Revenue from Contracts with Customers - Disaggregation of Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 366,965	$ 343,899	$ 1,057,611	$ 1,029,664
Lease licenses
Disaggregation of Revenue [Line Items]
Total revenue	78,917	70,693	237,000	239,953
Perpetual licenses
Disaggregation of Revenue [Line Items]
Total revenue	62,705	66,451	161,793	190,734
Software licenses
Disaggregation of Revenue [Line Items]
Total revenue	141,622	137,144	398,793	430,687
Maintenance
Disaggregation of Revenue [Line Items]
Total revenue	211,942	193,189	615,609	559,768
Service
Disaggregation of Revenue [Line Items]
Total revenue	13,401	13,566	43,209	39,209
Maintenance and service
Disaggregation of Revenue [Line Items]
Total revenue	$ 225,343	$ 206,755	$ 658,818	$ 598,977
Direct revenue, as a percentage of total revenue
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	74.90%	76.80%	75.70%	75.90%
Indirect revenue, as a percentage of total revenue
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	25.10%	23.20%	24.30%	24.10%