Stock-based Compensation and Awards (Tables)

9 Months Ended

Sep. 30, 2012

Stock-based Compensation and Awards [Abstract]

Summary of stock option activity

				Options outstanding
	Shares available for grant			Number of shares			Weighted average exercise price
Balances at December 31, 2011		1,343,978			4,505,153		$	4.25
Options granted		(790,364	)		790,364			15.11
Options exercised		—			(216,035	)		2.36
Options cancelled		197,371			(197,371	)		7.28
Options retired—2001 Plan		(120,874	)		—			—
Balances at September 30, 2012		630,111			4,882,111		$	5.98

Summary of restricted stock unit activity

	Shares outstanding
	Number of shares		Weighted average exercise price
Balances at December 31, 2011		—	$	—
Shares granted		17,500		21.88
Shared vested and paid out		—		—
Shares forfeited		—		—
Balances at September 30, 2012		17,500	$	21.88

Summary of stock awards outstanding and exercisable

Options outstanding at September 30, 2012									Options exercisable at September 30, 2012
Range of exercise price	Number outstanding		Weighted average remaining contractual life (years)		Weighted average exercise price		Aggregate intrinsic value ($’000s)		Number exercisable		Weighted average remaining contractual life (years)		Weighted average exercise price		Aggregate intrinsic value ($’000s)
$ 0.60 - $ 0.90		711,648		3.5	$	0.72				711,648		3.5	$	0.72
$ 2.40 - $ 3.00		2,054,633		7.2	$	2.57				1,356,049		7.0	$	2.52
$ 3.30 - $ 5.10		497,361		8.3	$	4.27				189,148		8.3	$	4.28
$ 7.17 - $13.80		1,290,813		9.2	$	11.65				173,539		9.1	$	11.65
$15.30 - $21.88		327,656		9.7	$	19.04				2,514		9.6	$	16.55
		4,882,111		7.5	$	5.98	$	12,323		2,432,898		6.2	$	2.79	$	9,257

Options outstanding at December 31, 2011									Options exercisable at December 31, 2011
Range of exercise price	Number outstanding		Weighted average remaining contractual life (years)		Weighted average exercise price		Aggregate intrinsic value ($’000s)		Number exercisable		Weighted average remaining contractual life (years)		Weighted average exercise price		Aggregate intrinsic value ($’000s)
$0.60 - $ 0.90		755,519		4.2	$	0.72				753,126		4.2	$	0.72
$2.40 - $ 3.00		2,285,729		8.0	$	2.54				1,107,324		7.7	$	2.48
$3.30 - $ 5.10		556,829		9.0	$	4.24				87,068		9.0	$	3.69
$9.30 - $11.70		907,076		9.8	$	11.53				198,228		9.8	$	11.67
		4,505,153		7.8	$	4.25	$	43,005		2,145,746		6.7	$	2.76	$	23,689

Summary of the components of stock-based compensation expense

	Three months  ended September 30,				Nine months  ended September 30,
	2012		2011		2012		2011
	(in thousands)
Cost of revenue	$	50	$	18	$	104	$	66
Research and development		346		117		695		285
Selling, general and administrative		666		248		1,391		433
	$	1,062	$	383	$	2,190	$	784

Share based payment award fair value assumptions and methodology

	Three months ended September 30,						Nine months ended September 30,
	2012			2011			2012			2011
Expected term (years)		6.25			—			6.25			6.25
Volatility		37	%		—	%		37	%		39	%
Risk-free rate		0.79-1.03	%		—	%		0.79-1.26	%		2.30-2.79	%
Dividend yield		—	%		—	%		—	%		—	%

	Three months ended September 30, 2012			Nine months  ended September 30, 2012
Expected term (years)		—			0.50
Volatility		—	%		30.8	%
Risk-free rate		—	%		0.15	%
Dividend yield		—	%		—	%