Segment Information (Revenues By Geographic Location) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 812,111	$ 798,929	$ 1,587,877	$ 1,659,874
Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	457,392	432,210	884,075	916,325
EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	275,396	277,313	553,195	570,960
APJ [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 79,323	$ 89,406	$ 150,607	$ 172,589