Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 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
	March 31,
	2018		2017
Cost of revenue	$	21	$	8
Selling, general and administrative		369		256
Research and development		77		48
Total stock-based compensation		467		312
Tax effect on stock-based compensation		—		—
Net effect on net income	$	467	$	312

Summary of weighted-average assumptions

	Three Months Ended		Three Months Ended
	March 31,		March 31,
	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 March 31, 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	(22)		2.94		$	97
Canceled and expired	—		—
Balance as of March 31, 2018	2,644	$	3.81	6.66	$	9,409
Options vested as of March 31, 2018 and unvested options expected to vest, net of forfeitures	2,616	$	3.79	6.64	$	9,352
Options exercisable as of March 31, 2018	1,694	$	3.41	5.81	$	6,523

Summary of restricted stock awards activity

A summary of activity related to restricted stock awards for the three months ended March 31, 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	4	$	7.35
Vested	—	$	—
Forfeited	—	$	—
Non-vested as of March 31, 2018	484	$	7.13