Stockholders' Equity - Additional Information (Details) - USD ($)			3 Months Ended		6 Months Ended
	Feb. 22, 2016	Dec. 23, 2013	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Feb. 28, 2014
Class of Stock [Line Items]
Common stock, shares authorized			175,000,000		175,000,000		175,000,000	175,000,000
Common stock, par value			$ 0.00001		$ 0.00001		$ 0.00001	$ 0.00001
Common stock, shares issued			38,008,933		38,008,933		30,662,218
Common stock, shares outstanding			38,008,933		38,008,933		30,662,218
Preferred stock, shares authorized			25,000,000		25,000,000		25,000,000
Preferred stock, par value			$ 0.00001		$ 0.00001		$ 0.00001
Preferred stock, shares issued			0		0		0
Preferred stock, shares outstanding			0		0		0
Common stock, shares reserved for future issuance			5,419,247		5,419,247		4,206,809
Stock-based compensation expense			$ 1,222,000	$ 1,095,000	$ 2,473,000	$ 2,223,000
Restricted Stock Units
Class of Stock [Line Items]
Vesting periods					3 years
Stock-based compensation expense			158,000	24,000	$ 264,000	32,000
Total compensation cost to be recognized			2,900,000		$ 2,900,000
Restricted Stock Units | Share Based Compensation Award Tranche One
Class of Stock [Line Items]
Vesting percentage					100.00%
Stock Options
Class of Stock [Line Items]
Shares issued	624,275
Stock-based compensation description					Options vest in installments of (i) 25% at the one year anniversary and (ii) in either 36 or 48 equal monthly or 12 equal quarterly installments beginning in the thirteenth month after the initial Vesting Commencement Date (as defined) or grant date, subject to the employee’s continuous service with the Company
Options expiration after the date of grant					10 years
Stock-based compensation expense			$ 1,021,000	908,000	$ 2,149,000	1,607,000
Stock Options | Share Based Compensation Award Tranche One
Class of Stock [Line Items]
Vesting percentage					25.00%
Restricted Stock
Class of Stock [Line Items]
Common stock, shares reserved for future issuance			159,640		159,640		216,716
Vesting periods		1 year
Stock-based compensation expense			$ 27,000	$ 142,000	$ 13,000	$ 542,000
Granted, Weighted-Average Grant Date Fair Value		$ 7.42
Restricted stock requisite service period description					The awards of restricted stock contained a performance condition wherein vesting is contingent upon the Company’s consummation of a liquidity event, as defined, prior to the fifth anniversary of the date of grant. Certain of the awards of restricted stock have a requisite service period that was complete upon grant. The remainder of the awards of restricted stock have a requisite service period of four years whereby the award vests 25% on the one year anniversary of the Vesting Commencement Date (as defined), then ratably on the first day of each calendar quarter for 12 quarters, subject to continuous service by the individual and achievement of the performance target
Grant-date fair value of restricted stock issued		$ 3,900,000
Award requisite service period		4 years
Restricted Stock | Share Based Compensation Award Tranche One
Class of Stock [Line Items]
Vesting percentage		25.00%
Restricted Stock | Employees
Class of Stock [Line Items]
Granted, Shares		450,224
Restricted Stock | Non Employees
Class of Stock [Line Items]
Granted, Shares		79,067
Stock-based compensation expense			$ 27,000
Maximum | Stock Options
Class of Stock [Line Items]
Vesting periods					48 months
Minimum | Stock Options
Class of Stock [Line Items]
Vesting periods					12 months
2014 Plans
Class of Stock [Line Items]
Common stock, shares reserved for future issuance			1,305,784		1,305,784		1,318,732		1,785,000
Incremental rate at which the shares reserved for issuance increase					3.00%
2014 Plans | Employees
Class of Stock [Line Items]
Granted, Shares					849,275
2014 Plans | Director
Class of Stock [Line Items]
Granted, Shares					87,500
2014 Plans | Restricted Stock Units
Class of Stock [Line Items]
Granted, Shares					402,338
2014 Plans | Maximum
Class of Stock [Line Items]
Common stock, shares reserved for future issuance			1,131,937		1,131,937
2014 Employee Stock Purchase Plan
Class of Stock [Line Items]
Maximum shares of common stock authorized to be issued			262,500		262,500
Percentage of increase on common stock authorized on each anniversary					1.00%
Number of common stock outstanding					739,611
Common stock shares authorized percentage under the plan					5.00%
Purchase price at the end of offering period					85.00%
Offering period					6 months
Shares issued			16,629
Stock-based compensation expense			$ 16,000		$ 47,000