Stock-Based Compensation (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Valuation model average assumptions
Expected term (years)	6 years 3 months 18 days
Expected volatility	50.60%
Risk-free interest rate	1.80%
Unamortized compensation
Total unamortized compensation expense	$ 15,758,000		$ 15,758,000		$ 18,938,000
Expected amortization period			3 years 2 months 23 days		3 years 11 months 1 day
Stock-based compensation expense
Total stock-based compensation expense	$ 1,211,000	$ 192,000	$ 3,691,000	$ 509,000
Common stock options
Valuation model average assumptions
Expected term (years)			6 years 3 months 18 days	7 years
Expected volatility			52.20%	50.00%
Risk-free interest rate			1.70%	2.10%
2015 Employee Stock Purchase Plan
Valuation model average assumptions
Expected term (years)			6 months
Expected volatility	45.20%		47.20%
Risk-free interest rate	0.07%		0.26%
Stock-based compensation expense
Total stock-based compensation expense	$ 45,000		$ 112,000
Cost of revenues
Stock-based compensation expense
Total stock-based compensation expense	57,000	19,000	173,000	$ 46,000
Research and development expenses
Stock-based compensation expense
Total stock-based compensation expense	564,000	54,000	1,673,000	127,000
Selling, general and administrative expenses
Stock-based compensation expense
Total stock-based compensation expense	$ 590,000	$ 119,000	$ 1,845,000	$ 336,000