Goodwill And Intangible Assets (Changes In Carrying Amounts Of Goodwill And Other Intangible Assets) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Goodwill [Line Items]
Balance as of January 1, 2017	$ 1,122,810
Goodwill acquired (Note 3)	31,253
Goodwill reclassified to noncurrent assets held for sale (1)	36,312
Goodwill written off related to sale of a business unit (2)(3)	(21,429)
Purchase accounting adjustments (4)	2,230
Foreign exchange translation	13,896
Balance as of September 30, 2017	1,107,988
Business Cloud Services Segment [Member]
Goodwill [Line Items]
Balance as of January 1, 2017	559,152
Goodwill acquired (Note 3)	31,253
Goodwill reclassified to noncurrent assets held for sale (1)	0
Goodwill written off related to sale of a business unit (2)(3)	(3,614)
Purchase accounting adjustments (4)	(766)
Foreign exchange translation	13,811
Balance as of September 30, 2017	599,836
Digital Media Segment [Member]
Goodwill [Line Items]
Balance as of January 1, 2017	563,658
Goodwill acquired (Note 3)	0
Goodwill reclassified to noncurrent assets held for sale (1)	36,312
Goodwill written off related to sale of a business unit (2)(3)	(17,815)
Purchase accounting adjustments (4)	(1,464)
Foreign exchange translation	85
Balance as of September 30, 2017	508,152
Cambridge [Member]
Goodwill [Line Items]
Goodwill written off related to sale of a business unit (2)(3)	(17,800)
Business Cloud Services Segment [Member]
Goodwill [Line Items]
Goodwill written off related to sale of a business unit (2)(3)	$ (3,600)