Segment Information (Revenues By Product Grouping) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Revenue	$ 812,111	$ 798,929	$ 1,587,877	$ 1,659,874
Workspace [Member]
Segment Reporting Information [Line Items]
Revenue	599,405	584,878	1,180,367	1,238,594
App Delivery and Security [Member]
Segment Reporting Information [Line Items]
Revenue	186,196	186,069	356,183	366,003
Professional Services [Member]
Segment Reporting Information [Line Items]
Revenue	$ 26,510	$ 27,982	$ 51,327	$ 55,277