Commitment and Contingencies (Details) $ in Thousands			9 Months Ended
	Sep. 30, 2015 USD ($) item	Dec. 31, 2014 item	Sep. 30, 2015 USD ($) item	Sep. 30, 2014 item
Commitments and Contingencies
Lease Term	6 years	6 years
Future minimum lease payments under non-cancelable operating leases
Remainder of 2015	$ 2,104		$ 2,104
2016	8,415		8,415
2017	8,401		8,401
2018	8,239		8,239
2019	7,583		7,583
Thereafter	10,133		10,133
Total future minimum lease payments	44,875		44,875
Cash held in escrow deposit	29,200		29,200
Letter of credit with Silicon Valley Bank	1,000		1,000
Cash received for future services	8,900		8,900
Short term portion of cash received	$ 1,500		$ 1,500
Accounts receivable. | Credit risk | Customers
Customer Concentration
Number of customers | item	3	4	3
Concentration risk (as a percent)	46.60%	69.90%
Accounts receivable. | Credit risk | Customer one
Customer Concentration
Concentration risk (as a percent)	18.50%	30.20%
Accounts receivable. | Credit risk | Customer two
Customer Concentration
Concentration risk (as a percent)	16.10%	16.00%
Accounts receivable. | Credit risk | Customer three
Customer Concentration
Concentration risk (as a percent)	12.00%	13.40%
Accounts receivable. | Credit risk | Customer four
Customer Concentration
Concentration risk (as a percent)		10.30%
Revenues. | Credit risk | Customers
Customer Concentration
Number of customers | item	1		1	2
Concentration risk (as a percent)			56.70%	36.60%
Revenues. | Credit risk | Customer one
Customer Concentration
Concentration risk (as a percent)				24.90%
Revenues. | Credit risk | Customer two
Customer Concentration
Concentration risk (as a percent)				11.70%