Intangible Assets (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Intangible assets
Gross Carrying Value	$ 42,290,000		$ 42,290,000
Accumulated amortization	(15,376,000)		(14,341,000)
Net Carrying Value	26,914,000		27,949,000
Amortization expense	1,000,000	1,100,000
Acquired technology and domain name
Intangible assets
Gross Carrying Value	31,090,000		31,090,000
Accumulated amortization	(11,551,000)		(10,788,000)
Net Carrying Value	19,539,000		20,302,000
Customer relationships
Intangible assets
Gross Carrying Value	6,300,000		6,300,000
Accumulated amortization	(2,682,000)		(2,491,000)
Net Carrying Value	3,618,000		3,809,000
Trade names
Intangible assets
Gross Carrying Value	4,900,000		4,900,000
Accumulated amortization	(1,143,000)		(1,062,000)
Net Carrying Value	$ 3,757,000		$ 3,838,000