Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Indirect sales channel revenue	24.46%	24.10%	23.86%	24.30%
Total revenue	$ 289,418	$ 275,585	$ 878,204	$ 792,914
Lease license
Total revenue	43,202	93,956	148,795	279,855
Perpetual license
Total revenue	65,901	62,624	201,501	168,513
Software licenses
Total revenue	109,103	156,580	350,296	448,368
Maintenance
Total revenue	171,463	112,300	500,962	324,338
Service
Total revenue	8,852	6,705	26,946	20,208
Maintenance and service
Total revenue	$ 180,315	$ 119,005	$ 527,908	$ 344,546
Calculated under Revenue Guidance in Effect before Topic 606
Indirect sales channel revenue	23.51%		23.46%
Total revenue	$ 301,956		$ 880,551
Calculated under Revenue Guidance in Effect before Topic 606 | Lease license
Total revenue	106,461		308,699
Calculated under Revenue Guidance in Effect before Topic 606 | Perpetual license
Total revenue	60,145		173,957
Calculated under Revenue Guidance in Effect before Topic 606 | Software licenses
Total revenue	166,606		482,656
Calculated under Revenue Guidance in Effect before Topic 606 | Maintenance
Total revenue	126,436		370,847
Calculated under Revenue Guidance in Effect before Topic 606 | Service
Total revenue	8,914		27,048
Calculated under Revenue Guidance in Effect before Topic 606 | Maintenance and service
Total revenue	$ 135,350		$ 397,895