Goodwill and Intangible Assets, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill and Intangible Assets, Net
Intangible assets, gross	$ 13,160	$ 11,222
Less accumulated amortization	(7,705)	(4,146)
Net Carrying Amount	5,455	7,076
Goodwill	29,201	29,201
Goodwill and intangible assets, net	34,656	36,277
Amortization expense	3,559	2,256	$ 717
Estimated future amortization
2016	3,383
2017	1,943
2018	100
2019	29
Net Carrying Amount	5,455	7,076
Developed technology
Goodwill and Intangible Assets, Net
Intangible assets, gross	6,050	$ 6,050
Net Carrying Amount	$ 2,915
Weighted Average Remaining Useful Life	1 year 10 months 24 days	2 years 10 months 24 days
Estimated future amortization
2016	$ 1,508
2017	1,407
Net Carrying Amount	2,915
Domain names
Goodwill and Intangible Assets, Net
Intangible assets, gross	950	$ 950
Net Carrying Amount	$ 409
Weighted Average Remaining Useful Life	2 years 9 months 18 days	3 years 7 months 6 days
Estimated future amortization
2016	$ 180
2017	100
2018	100
2019	29
Net Carrying Amount	409
Customer relationships
Goodwill and Intangible Assets, Net
Intangible assets, gross	1,600	$ 1,600
Net Carrying Amount	$ 315
Weighted Average Remaining Useful Life	9 months 18 days	1 year 7 months 6 days
Estimated future amortization
2016	$ 315
Net Carrying Amount	315
Non-compete agreements
Goodwill and Intangible Assets, Net
Intangible assets, gross	580	$ 580
Net Carrying Amount	$ 294
Weighted Average Remaining Useful Life	2 years	3 years
Estimated future amortization
2016	$ 150
2017	144
Net Carrying Amount	294
Capitalized software development costs
Goodwill and Intangible Assets, Net
Intangible assets, gross	3,980	$ 2,042
Net Carrying Amount	$ 1,522
Weighted Average Remaining Useful Life	1 year 2 months 12 days	1 year 2 months 12 days
Software development costs capitalized during period	$ 1,900	$ 700
Amortization expense	1,200	$ 300	$ 200
Estimated future amortization
2016	1,230
2017	292
Net Carrying Amount	$ 1,522