Revenue from Contracts with Customers - Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021 USD ($) division	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) division	Sep. 30, 2020 USD ($)
Disaggregation of Revenue [Line Items]
Revenue	$ 860,333	$ 792,845	$ 2,555,865	$ 2,351,862
Number of groups | division	2		2
Security Technology Group
Disaggregation of Revenue [Line Items]
Revenue	$ 334,649	265,869	$ 969,996	765,485
Edge Technology Group
Disaggregation of Revenue [Line Items]
Revenue	525,684	526,976	1,585,869	1,586,377
U.S.
Disaggregation of Revenue [Line Items]
Revenue	448,792	437,381	1,361,525	1,309,979
International
Disaggregation of Revenue [Line Items]
Revenue	$ 411,541	$ 355,464	$ 1,194,340	$ 1,041,883