Intangible Assets (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Intangible assets
Gross Carrying Value	$ 42,290,000	$ 41,995,000
Accumulated amortization	(14,341,000)	(10,161,000)
Net Carrying Value	27,949,000	31,834,000
Weighted average useful life in years	10 years 2 months 12 days	10 years 2 months 23 days
Amortization expense	4,251,000	4,405,000	4,476,000
Acquired technology and domain name
Intangible assets
Gross Carrying Value	31,090,000	30,725,000
Accumulated amortization	(10,788,000)	(7,624,000)
Net Carrying Value	20,302,000	23,101,000
Weighted average useful life in years	9 years 8 months 12 days	9 years 9 months
Amortization expense	3,164,000	3,318,000	3,343,000
Customer relationships
Intangible assets
Gross Carrying Value	6,300,000	6,300,000
Accumulated amortization	(2,491,000)	(1,732,000)
Net Carrying Value	3,809,000	4,568,000
Weighted average useful life in years	8 years 11 months 19 days	8 years 11 months 19 days
Amortization expense	760,000	760,000	760,000
Trade names
Intangible assets
Gross Carrying Value	4,900,000	4,970,000
Accumulated amortization	(1,062,000)	(805,000)
Net Carrying Value	3,838,000	4,165,000
Weighted average useful life in years	15 years	14 years 9 months 18 days
Amortization expense	327,000	327,000	373,000
Domain name
Intangible assets
Intangible assets acquired	$ 400,000