Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2017

Equity [Abstract]

Schedule of Number of Shares of Common Stock Reserved for Future Issuance

The Company has reserved for future issuance the following number of shares of common stock:

	September 30, 2017		December 31, 2016
Unvested restricted stock		1,386,942		1,297,054
Common stock options		849,953		1,267,329
Shares available for issuance under the 2013 Stock Option and    Incentive Plan		3,250,408		2,398,031
Shares available for issuance under the 2013 Employee Stock    Purchase Plan		788,503		788,503
		6,275,806		5,750,917

Summary of Roll Forward of Restricted Stock Activity Pursuant to the 2010 and 2013 Stock Plan

The following table shows a roll forward of restricted stock activity pursuant to the 2010 Stock Plan and the 2013 Stock Plan:

	Number of Shares
Unvested at December 31, 2016		1,297,054
Granted		775,819
Vested		(520,098	)
Cancelled		(165,833	)
Unvested at September 30, 2017		1,386,942

Summary of Stock Option Activity Under the 2010 Stock Plan and the 2013 Stock Plan

A summary of stock option activity under the 2010 Stock Plan and the 2013 Stock Plan for the nine months ended September 30, 2017 is as follows:

	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In Years)		Aggregate Intrinsic Value
								(in thousands)
Outstanding as of December 31, 2016		1,267,329		$	16.22		6.6	$	8,355
Granted		—			—
Exercised		(366,044	)		11.28
Cancelled		(51,332	)		24.39
Outstanding as of September 30, 2017		849,953		$	17.86		5.9	$	19,500
Exercisable as of September 30, 2017		746,590		$	16.43		5.8	$	18,061

Recorded Stock-Based Compensation Expense in the Consolidated Statements of Operations and Comprehensive Loss

The Company recorded stock-based compensation expense in the statements of operations and comprehensive loss as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Cost of revenue	$	294	$	668	$	1,952	$	1,488
Selling and marketing		824		1,112		3,341		2,768
General and administrative		2,872		2,800		8,809		6,393
Research and development		945		1,276		3,958		2,877
Total	$	4,935	$	5,856	$	18,060	$	13,526

Weighted-Average Assumptions Used to Estimate Fair Value of Stock Options Using Black-Scholes Option Pricing Model

There were no stock options granted during the three and nine months ended September 30, 2017 and three months ended September 30, 2016. The weighted-average assumptions used to estimate the fair value of stock options using the Black-Scholes option pricing model for the nine months ended September 30, 2016 were as follows:

	Nine Months Ended
	September 30, 2016
Expected volatility		59.2	%
Risk-free interest rate		1.9	%
Expected option term (in years)		6.25
Expected dividend yield		0.0	%