Intangible Assets - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Intangible assets
Gross Carrying Value	$ 42,290	$ 42,290
Accumulated amortization	(26,378)	(22,516)
Net Carrying Value	15,912	19,774
Acquired technology and domain name
Intangible assets
Gross Carrying Value	31,090	31,090
Accumulated amortization	(19,911)	(16,876)
Net Carrying Value	11,179	14,214
Customer relationships
Intangible assets
Gross Carrying Value	6,300	6,300
Accumulated amortization	(4,425)	(3,925)
Net Carrying Value	1,875	2,375
Tradenames
Intangible assets
Gross Carrying Value	4,900	4,900
Accumulated amortization	(2,042)	(1,715)
Net Carrying Value	$ 2,858	$ 3,185