Segment Information - Reportable Segment Information (Total Assets, Capital Expenditures, Depreciation And Amortization) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Other Significant Reconciling Item [Line Items]
Assets	$ 2,560,830	$ 2,453,093
Capital expenditures	56,379	39,595	$ 24,746
Total capital expenditures	56,379	39,595	24,746
Total depreciation and amortization	187,174	162,041	122,091
Cloud Services
Segment Reporting, Other Significant Reconciling Item [Line Items]
Assets	1,047,245	1,078,577
Capital expenditures	13,832	7,031	6,113
Total depreciation and amortization	60,754	68,436	79,533
Digital Media
Segment Reporting, Other Significant Reconciling Item [Line Items]
Assets	1,455,620	1,317,113
Capital expenditures	42,547	32,564	18,633
Total depreciation and amortization	122,843	93,605	42,558
Reportable segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Assets	2,502,865	2,395,690
Capital expenditures	56,379	39,595	24,746
Total depreciation and amortization	183,597	162,041	122,091
Corporate
Segment Reporting, Other Significant Reconciling Item [Line Items]
Assets	57,965	57,403
Capital expenditures	0	0	0
Total depreciation and amortization	$ 3,577	$ 0	$ 0