Summary of Significant Accounting Policies - Schedule of Revenue Disaggregated by Type of Revenue and Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation Of Revenue [Line Items]
Total revenues	$ 245,856	$ 213,033	$ 490,649	$ 414,737
Americas (principally the U.S.)
Disaggregation Of Revenue [Line Items]
Total revenues	214,390	180,217	425,120	350,120
Europe, Middle East, and Africa
Disaggregation Of Revenue [Line Items]
Total revenues	22,606	21,977	47,232	42,411
Asia Pacific
Disaggregation Of Revenue [Line Items]
Total revenues	8,860	10,839	18,297	22,206
Cloud and Related Solutions
Disaggregation Of Revenue [Line Items]
Total revenues	222,183	187,401	441,773	364,917
Software and Services
Disaggregation Of Revenue [Line Items]
Total revenues	12,173	13,331	25,201	25,290
Maintenance
Disaggregation Of Revenue [Line Items]
Total revenues	$ 11,500	$ 12,301	$ 23,675	$ 24,530