Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenues	$ 469,240	$ 356,976	$ 330,984	$ 332,393	$ 405,588	$ 344,141	$ 322,432	$ 299,893	$ 1,489,593	$ 1,372,054	$ 1,207,295
Point in time
Disaggregation of Revenue [Line Items]
Total revenues									27,685	32,983	4,752
Over time
Disaggregation of Revenue [Line Items]
Total revenues									1,461,908	1,339,071	1,202,543
Reportable segments
Disaggregation of Revenue [Line Items]
Total revenues									1,489,592	1,372,046	1,207,289
Reportable segments | Digital Media
Disaggregation of Revenue [Line Items]
Total revenues									811,360	710,511	609,374
Reportable segments | Digital Media | Advertising
Disaggregation of Revenue [Line Items]
Total revenues									616,197	515,702	468,325
Reportable segments | Digital Media | Subscription
Disaggregation of Revenue [Line Items]
Total revenues									186,718	185,559	138,689
Reportable segments | Digital Media | Other
Disaggregation of Revenue [Line Items]
Total revenues									8,445	9,250	2,360
Reportable segments | Cloud Services
Disaggregation of Revenue [Line Items]
Total revenues									678,461	661,835	597,975
Reportable segments | Cloud Services | Subscription
Disaggregation of Revenue [Line Items]
Total revenues									678,013	660,814	597,281
Reportable segments | Cloud Services | Other
Disaggregation of Revenue [Line Items]
Total revenues									448	1,021	694
Corporate, Non-Segment
Disaggregation of Revenue [Line Items]
Total revenues									1	8	6
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Total revenues									$ (229)	$ (300)	$ (60)