Revenues Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Total revenues	$ 346,059	$ 292,724	$ 287,889	$ 280,623	$ 316,380	$ 273,616	$ 273,174	$ 254,669	$ 1,207,295	$ 1,117,838	$ 874,255
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Total revenues									4,752	22,559	14,459
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Total revenues									1,202,543	1,095,279	859,796
Digital Media
Disaggregation of Revenue [Line Items]
Total revenues									609,374	538,939	307,463
Digital Media | Advertising [Member]
Disaggregation of Revenue [Line Items]
Total revenues									468,325	455,647	274,763
Digital Media | Subscription [Member]
Disaggregation of Revenue [Line Items]
Total revenues									138,689	70,794	32,700
Digital Media | Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues									2,360	12,498	0
Cloud Services
Disaggregation of Revenue [Line Items]
Total revenues									597,975	578,956	566,938
Cloud Services | Subscription [Member]
Disaggregation of Revenue [Line Items]
Total revenues									597,281	574,197	562,345
Cloud Services | Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues									694	4,759	4,593
Corporate
Disaggregation of Revenue [Line Items]
Total revenues									6	0	0
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Total revenues									$ (60)	$ (57)	$ (146)