Shareholders' Equity (Tables)

9 Months Ended

Sep. 30, 2019

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 September 30,						Nine Months Ended September 30,
	2019			2018			2019			2018
Dividend yield		0	%		0	%		0	%		0	%
Expected life	5.6 years			4.4 years			5.8 years			5.3 years
Expected volatility		64	%		56	%		64	%		55	%
Risk-free interest rate		1.6	%		2.7	%		2.1	%		2.5	%

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 September 30,				Nine Months Ended September 30,
	2019		2018		2019			2018
Cost of revenue — Edge to Cloud	$	1	$	11	$	10		$	30
Selling, general and administrative		175		237		373			421
Research and development		12		57		(12	)		169
Total stock-based compensation expense	$	188	$	305	$	371		$	620
Per diluted share	$	0.01	$	0.02	$	0.03		$	0.05

Summary of Stock Option Activity

The following table summarizes stock option activity under the Plans:

						Weighted Average
						Remaining
	Number of			Weighted Average		Contractual Life		Aggregate
	Shares			Exercise Price		(in years)		Intrinsic Value
Balance at December 31, 2018		1,390,012		$	4.77		6.83	$	—
Granted		933,423			1.70
Exercised		—			—
Forfeited		(218,889	)		4.98
Expired		(467,490	)		5.00
Balance at September 30, 2019		1,637,056		$	2.93		7.67	$	505
Vested and expected to vest at September 30, 2019		1,349,818		$	3.17		7.28	$	343
Exercisable at September 30, 2019		596,324		$	4.69		4.67	$	—

Summary of Certain Additional Information about Stock Options

The following table summarizes certain information about stock options:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019		2018
Weighted average grant-date fair value of options granted during the period	$	1.23	$	1.02	$	1.70	$	1.89
Options in-the-money (in shares)		—		26,000		—		26,000
Aggregate intrinsic value of options exercised during the period	$	—	$	—	$	—	$	1,853

Summary of Restricted Stock Unit Activity

The following table summarizes RSU activity under the Plans:

	Number of			Weighted Average
	Shares			Award Price
Unvested at December 31, 2018		186,516		$	2.88
Granted		225,693			1.44
Vested		(204,679	)		2.19
Forfeited		(34,643	)		4.68
Unvested at September 30, 2019		172,887		$	1.46
Expected to vest after September 30, 2019		159,795		$	1.46

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 September 30, 2019:

	September 30, 2019
Stock options outstanding		1,637,056
Restricted stock units outstanding		172,887
Stock options and restricted stock units available for future grant		1,637,806
Common stock reserved for future issuance		3,447,749