Goodwill and Intangible Assets (Changes in Carrying Amounts of Goodwill) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 1,591,474
Goodwill acquired	3,849
Purchase accounting adjustments	513
Foreign exchange translation	1,848
Ending balance	1,597,684
Operating Segments | Digital Media
Goodwill [Roll Forward]
Beginning balance	1,065,989
Goodwill acquired	3,849
Purchase accounting adjustments	513
Foreign exchange translation	540
Ending balance	1,070,891
Operating Segments | Cybersecurity and Martech
Goodwill [Roll Forward]
Beginning balance	525,485
Goodwill acquired	0
Purchase accounting adjustments	0
Foreign exchange translation	1,308
Ending balance	$ 526,793