Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2018

Stock-Based Compensation

Summary of compensation costs related to stock-based awards

The following table summarizes compensation costs related to our stock-based awards (in thousands, except per share data):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2018		2017		2018		2017
Cost of revenue	$	21	$	7	$	42	$	15
Selling, general and administrative		368		252		737		508
Research and development		75		51		152		99
Total stock-based compensation		464		310		931		622
Tax effect on stock-based compensation		—		—		—		—
Net effect on net income	$	464	$	310	$	931	$	622

Summary of weighted-average assumptions

	Six Months Ended		Six Months Ended
	June 30,		June 30,
	2018		2017
Expected term (in years)	—		5.9
Volatility	—	%	46.71	%
Expected dividend	—	%	—	%
Risk-free interest rate	—	%	2.08	%

Summary of stock option activity

The following table summarizes the stock option transactions during the three months ended June 30, 2018 (in thousands, except per share data):

				Weighted
				average
		Weighted-		Remaining
	Number of	average		Contractual	Aggregate
	Options	Exercise		Life	Intrinsic
Stock Options	Outstanding	Price		(in years)	Value
Balance as of January 1, 2018	2,666	$	3.81	6.87	$	13,149
Granted	—		—
Exercised	(66)		2.68
Canceled and expired	(2)		5.21
Balance as of June 30, 2018	2,598	$	3.83	6.44	$	8,715
Options vested as of June 30, 2018 and unvested options expected to vest, net of forfeitures	2,576	$	3.81	6.42	$	8,678
Options exercisable as of June 30, 2018	1,771	$	3.42	5.71	$	6,452

Summary of restricted stock awards activity

A summary of activity related to restricted stock awards for the six months ended June 30, 2018 is presented below (in thousands, except per share data):

		Weighted-Average
		Grant Date
Stock Awards	Shares	Fair Value
Non-vested as of January 1, 2018	480	$	7.13
Granted	35	$	7.49
Vested	(49)	$	6.19
Forfeited	(3)	$	9.50
Non-vested as of June 30, 2018	463	$	7.24