Shareholders' Equity (Tables)

3 Months Ended

Mar. 31, 2017

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Fair Values of Stock Option Grants Estimated with Weighted Average Assumptions

The fair values of our stock option grants were estimated with the following weighted average assumptions:

	Three Months Ended March 31,
	2017			2016
Dividend yield		0	%		0	%
Expected life	3.3 years			3.4 years
Expected volatility		53	%		55	%
Risk-free interest rate		1.7	%		1.1	%

Stock-Based Compensation Expense

The impact on our results of operations from stock-based compensation expense was as follows (in thousands, except per share amounts):  

	Three Months Ended March 31,
	2017		2016
Cost of revenue — service	$	65	$	138
Selling, general and administrative		284		249
Research and development		50		26
Total stock-based compensation expense	$	399	$	413
Per diluted share	$	0.03	$	0.03

Summary of Stock Option Activity

The following table summarizes stock option activity under the Plans for the three-month period ended March 31, 2017:

Stock Options	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value
Balance at January 1, 2017		1,846,768		$	4.84		8.19	$	2,138,361
Granted		39,500			5.59
Exercised		(21,412	)		4.11
Forfeited		(32,130	)		5.09
Expired		(4,573	)		5.89
Balance at March 31, 2017		1,828,153		$	4.86		8.06	$	1,513,726
Vested and expected to vest at March 31, 2017		1,677,043		$	4.81		7.94	$	1,473,638
Exercisable at March 31, 2017		815,565		$	4.20		6.64	$	1,200,208

Summary of Certain Information about Stock Options

The following table summarizes certain information about stock options:

	Three Months Ended March 31,
	2017		2016
Weighted-average grant-date fair value of option    grants for the period	$	3.01	$	3.06
Options in-the-money at period end		1,224,182		1,338,733
Aggregate intrinsic value of options exercised	$	40,421	$	49,330

Summary of Restricted Stock Unit Activity

The following table summarizes RSU activity for the three-month period ended March 31, 2017:

	Number of Shares			Weighted Average Grant Date Fair Value
Unvested at January 1, 2017		119,606		$	5.60
Granted		—			—
Vested		(15,839	)		5.72
Forfeited		—			—
Unvested at March 31, 2017		103,767		$	5.58
Expected to vest after March 31, 2017		89,585		$	5.60

Summary of Shares of Common Stock Reserved for Future Issuance under Plans

The following table summarizes our shares of common stock reserved for future issuance under the Plans as of March 31, 2017:

Stock options outstanding	1,828,153
RSUs outstanding	103,767
Stock awards available for future grant	686,363
Common stock reserved for future issuance	2,618,283