Shareholders' Equity (Tables)

12 Months Ended

Dec. 31, 2017

Stockholders' Equity Note [Abstract]

Schedule of Stock Option Activity

The following is a summary of stock option activity:

	Number of shares		Weighted average exercise price
Options outstanding as of December 31, 2016:	2,505,702		$	2.46
Granted	44,000		4.20
Exercised	(991,332	)	2.76
Canceled and forfeited	(154,061	)	2.13
Expired	(98,559	)	5.43
Options outstanding as of December 31, 2017:	1,305,750		$	2.11

Schedue of Shares Authorized under Stock Option Plans, by Exercise Price Range

The following table summarizes information about options outstanding as of December 31, 2017:

	Options Outstanding				Options Exercisable
Range of exercise prices	Number outstanding as of December 31, 2017	Weighted average remaining contractual life	Weighted average exercise price		Number exercisable as of December 31, 2017	Weighted average exercise price
$0.60 - $0.60	300,000	1.22	$	0.60	300,000	$	0.60
0.68 - 2.43	205,541	1.03	1.16		201,333	1.14
2.46 - 2.46	352,000	3.99	2.46		169,708	2.46
2.67 - 3.15	385,209	1.72	3.03		312,459	3.09
3.27 - 6.16	63,000	3.93	4.72		27,272	4.86
$0.60 - $6.16	1,305,750	2.22	$	2.11	1,010,772	$	1.94

Schedule of Stock Options Outstanding, Vested and Expected to Vest

Options outstanding that have vested and are expected to vest as of December 31, 2017 are as follows:

	Number of shares	Weighted average exercise price		Weighted average remaining contractual term	Aggregate intrinsic value
Vested	1,010,772	$	1.90	1.59	$	4,473
Expected to vest	263,380	2.77		4.34	938
Total	1,274,152	$	2.08	2.16	$	5,411

Schedule of Restricted Stock Units Activity

The following is a summary of restricted stock activity:

	Number of shares		Weighted average grant date fair value
Unvested at December 31, 2016:	1,698,500		$	2.93
Granted	1,514,527		4.87
Vested	(857,208	)	3.63
Canceled	(53,217	)	3.33
Unvested at December 31, 2017:	2,302,602		$	3.94
Expected to vest after December 31, 2017	1,925,115		$	3.94

Stock-Based Compensation, Valuation Assumptions

The fair value of stock-based compensation was determined using the Black-Scholes option pricing model and the following weighted average assumptions:

	Year Ended December 31,
	2017		2016		2015
Stock Option Plans:
Risk free interest rate	1.85	%	1.37	%	1.52	%
Expected dividend yield	0	%	0	%	0	%
Expected term (in years)	5.00		5.00		5.00
Volatility	75	%	74	%	68	%
Employee Stock Purchase Plan:
Risk free interest rate	1.09	%	0.20	%	0.28	%
Expected dividend yield	0	%	0	%	0	%
Expected term (in years)	1.07		1.12		1.10
Volatility	65	%	84	%	89	%