Segment Information Reportable Segment Information (Total Assets, Capital Expenditures, Depreciation And Amortization) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total assets	$ 2,452,218		$ 2,453,093
Property, Plant and Equipment, Additions	13,165	$ 9,660
Depreciation, Depletion and Amortization, Nonproduction	42,618	39,322
Business Cloud Services Segment [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total assets	1,108,992		1,078,577
Property, Plant and Equipment, Additions	2,874	1,456
Depreciation, Depletion and Amortization, Nonproduction	14,378	16,764
Digital Media Segment [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total assets	1,273,691		1,317,113
Property, Plant and Equipment, Additions	10,291	8,204
Depreciation, Depletion and Amortization, Nonproduction	27,114	22,558
Operating Segments [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total assets	2,382,683		2,395,690
Property, Plant and Equipment, Additions	13,165	9,660
Depreciation, Depletion and Amortization, Nonproduction	41,492	39,322
Corporate [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total assets	69,535		$ 57,403
Property, Plant and Equipment, Additions	0	0
Depreciation, Depletion and Amortization, Nonproduction	$ 1,126	$ 0