Stock Option Plans (Tables)

9 Months Ended

Sep. 30, 2013

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Employee Stock Option activity and Related Information

A summary of the Company’s employee stock option activity and related information follows:

	Shares			Weighted- average exercise price per share		Weighted- average remaining contractual term (in years)		Aggregate intrinsic value (in thousands)
Outstanding at December 31, 2011		686,312		$	2.24
Granted		1,114,143			2.28
Cancelled		(29,141	)		1.98
Exercised		(85,135	)		2.15
Outstanding at December 31, 2012		1,686,179		$	2.28		8.59	$	7,486
Granted (unaudited)		410,249			7.38
Canceled (unaudited)		(48,730	)		2.16
Exercised (unaudited)		(174,207	)		2.17
Outstanding at September 30, 2013 (unaudited)		1,873,491		$	3.41		8.12	$	14,219
December 31, 2012:
Options vested and expected to vest		1,532,508		$	2.28		8.54	$	6,820
Options exercisable		1,196,057		$	2.35		8.47	$	5,223
September 30, 2013:
Options vested and expected to vest (unaudited)		1,122,277		$	4.14		8.51	$	7,699
Options exercisable (unaudited)		751,225		$	2.32		7.53	$	6,521

Company's Options Outstanding

The following table summarizes information about the Company’s options outstanding at December 31, 2012:

	Options Outstanding				Options Exercisable
Exercise Price	Number of Shares		Weighted- Average Remaining Contractual Life in Years		Number of Shares		Weighted- Average Remaining Contractual Life in Years
$0.32		4,373		2.58		4,373		2.58
0.96		1,353		3.17		1,353		3.17
1.92		942,327		9.22		580,052		9.22
2.24		601,136		7.45		490,180		7.42
3.84		11,118		5.77		11,100		5.77
5.12		125,872		9.79		108,999		9.79
		1,686,179				1,196,057

Fair Value Of Employee Option Granted

The fair value of each employee option grant for the years ended December 31, 2010, 2011 and 2012 and the nine months ended September 30, 2012 and 2013 was estimated on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions:

	Years Ended December 31,						Nine Months Ended September 30,
	2010		2011		2012		2012		2013
							(Unaudited)
Risk-free interest rates		2.42%–3.14%		2.2%–3.14%		0.85%–1.44%		0.85%–1.44%		1.05%–1.90%
Expected term (years)		6.25		6.25		6.25		6.25		6.25
Expected dividend yield		—		—		—		—		—
Volatility		92.4%		73.0%		54.0%–61.0%		61.0%		57.0%-61.0%

Stock Options Granted

Information on stock options granted during the year ended December 31, 2012 and the nine months ended September 30, 2013 is summarized as follows:

	Number of Options Granted		Exercise Price		Estimated Value Per Common Share		Intrinsic Value Per Share
2012
March 1		730,860	$	1.92	$	2.24	$	0.32
March 26		39,000		1.92		2.24		0.32
April 19		87,563		1.92		2.56		0.64
May 25		106,813		1.92		2.88		0.96
July 17		22,469		1.92		3.20		1.28
September 17		1,563		1.92		4.16		2.24
October 16		125,875		5.12		5.12		—
		1,114,143
2013
January 10 (unaudited)		213,032		6.72		6.72	$	—
March 1 (unaudited)		82,000		6.72		8.96		2.24
May 13 (unaudited)		19,500		8.96		12.16		3.20
June 25 (unaudited)		11,686		10.00		10.00		—
July 10 (unaudited)		59,914		8.45		8.45		—
July 18 (unaudited)		24,117		9.46		9.46		—
		410,249

Stock Compensation

Stock compensation was recorded as follows:

	Years Ended December 31,						Nine Months Ended September 30,
	2010		2011		2012		2012		2013
	(In thousands)
							(Unaudited)
Cost of revenue	$	3	$	4	$	71	$	59	$	34
Research and development		26		26		204		163		201
Selling, general and administrative		115		213		470		344		531
Total stock-based compensation expense	$	144	$	243	$	745	$	566	$	766