Goodwill And Intangible Assets (Changes In Carrying Amounts Of Goodwill And Other Intangible Assets) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($)
Goodwill [Line Items]
Balance as of January 1, 2016	$ 807,661
Goodwill, Acquired During Period	56,479
Goodwill, Purchase Accounting Adjustments	(4,115)
Foreign Exchange Translation	(6,234)
Balance as of September 30, 2016	853,791
Business Cloud Services Segment [Member]
Goodwill [Line Items]
Balance as of January 1, 2016	502,718
Goodwill, Acquired During Period	56,479
Goodwill, Purchase Accounting Adjustments	816
Foreign Exchange Translation	(6,073)
Balance as of September 30, 2016	553,940
Digital Media Segment [Member]
Goodwill [Line Items]
Balance as of January 1, 2016	304,943
Goodwill, Acquired During Period	0
Goodwill, Purchase Accounting Adjustments	(4,931)
Foreign Exchange Translation	(161)
Balance as of September 30, 2016	$ 299,851