Segment Information (Revenues By Geographic Location) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 767,170	$ 732,901	$ 2,427,044	$ 2,200,741
Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	414,341	418,301	1,330,666	1,251,729
EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	276,494	236,081	847,454	713,282
APJ [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 76,335	$ 78,519	$ 248,924	$ 235,730