Revenues - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Total revenues	$ 280,623	$ 254,669
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Total revenues	1,075	4,619
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Total revenues	279,548	250,050
Digital Media Segment [Member]
Disaggregation of Revenue [Line Items]
Total revenues	131,161	113,131
Digital Media Segment [Member] | Advertising [Member]
Disaggregation of Revenue [Line Items]
Total revenues	96,338	92,488
Digital Media Segment [Member] | Subscription [Member]
Disaggregation of Revenue [Line Items]
Total revenues	29,350	13,401
Digital Media Segment [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues	5,473	7,242
Business Cloud Services Segment [Member]
Disaggregation of Revenue [Line Items]
Total revenues	149,485	141,544
Business Cloud Services Segment [Member] | Subscription [Member]
Disaggregation of Revenue [Line Items]
Total revenues	149,322	140,332
Business Cloud Services Segment [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues	163	1,212
Corporate [Member]
Disaggregation of Revenue [Line Items]
Total revenues	1	0
Intersegment Elimination [Member]
Disaggregation of Revenue [Line Items]
Total revenues	$ (24)	$ (6)