Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Goodwill and Intangible Assets
Intangible assets, gross	$ 13,005		$ 13,005		$ 11,222
Less accumulated amortization	(6,696)		(6,696)		(4,146)
Intangible assets, net	6,309		6,309		7,076
Goodwill	29,201		29,201		29,201
Goodwill and intangible assets, net	35,510		35,510		36,277
Amortization expense	922	$ 586	2,550	$ 1,606
Estimated future amortization
Three Months Ending December 31, 2015	1,001		1,001
2016	3,279		3,279
2017	1,900		1,900
2018	100		100
2019	29		29
Intangible assets, net	6,309		6,309		7,076
Developed technology
Goodwill and Intangible Assets
Intangible assets, gross	6,050		6,050		$ 6,050
Intangible assets, net	3,291		$ 3,291
Weighted Average Remaining Useful Life			2 years 2 months 12 days		2 years 10 months 24 days
Estimated future amortization
Three Months Ending December 31, 2015	377		$ 377
2016	1,508		1,508
2017	1,406		1,406
Intangible assets, net	3,291		3,291
Domain names
Goodwill and Intangible Assets
Intangible assets, gross	950		950		$ 950
Intangible assets, net	455		$ 455
Weighted Average Remaining Useful Life			3 years		3 years 7 months 6 days
Estimated future amortization
Three Months Ending December 31, 2015	46		$ 46
2016	180		180
2017	100		100
2018	100		100
2019	29		29
Intangible assets, net	455		455
Customer relationships
Goodwill and Intangible Assets
Intangible assets, gross	1,600		1,600		$ 1,600
Intangible assets, net	452		$ 452
Weighted Average Remaining Useful Life			1 year		1 year 7 months 6 days
Estimated future amortization
Three Months Ending December 31, 2015	137		$ 137
2016	315		315
Intangible assets, net	452		452
Non-compete agreements
Goodwill and Intangible Assets
Intangible assets, gross	580		580		$ 580
Intangible assets, net	332		$ 332
Weighted Average Remaining Useful Life			2 years 2 months 12 days		3 years
Estimated future amortization
Three Months Ending December 31, 2015	38		$ 38
2016	150		150
2017	144		144
Intangible assets, net	332		332
Capitalized software development costs
Goodwill and Intangible Assets
Intangible assets, gross	3,825		3,825		$ 2,042
Intangible assets, net	1,779		$ 1,779
Weighted Average Remaining Useful Life			1 year 3 months 18 days		1 year 2 months 12 days
Estimated future amortization
Three Months Ending December 31, 2015	403		$ 403
2016	1,126		1,126
2017	250		250
Intangible assets, net	$ 1,779		$ 1,779