Stock Plans (Tables)

12 Months Ended

Dec. 31, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock options weighted-average assumptions

The fair value of stock options was estimated on the date of grant using the Black-Scholes valuation model with the following weighted-average assumptions:

	Year Ended December 31, 2013
Expected dividends	—
Exercise price	$	6.80
Expected volatility range	68.6		%
Risk-free interest rate range	1.1		%
Expected term/life (in years)	4.8
Fair value per share	$	3.72

Aggregate stock option activity

The following table summarizes total aggregate stock option activity for the period December 31, 2012 through December 31, 2013:

	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Balance at December 31, 2012	923,756		$	11.67
Granted	175,306		7.56
Exercised	(19,500	)	7.34
Canceled	(217,256	)	10.43
Balance at December 31, 2013	862,306		$	11.24	4.58	$	150,166
Vested or expected to vest at December 31, 2013	848,161		$	11.31	4.50	$	137,004
Exercisable at December 31, 2013	759,936		$	11.51	4.04	$	77,416

Restricted stock award activity

The following table summarizes restricted stock award activity for the period December 31, 2012 through December 31, 2013 (in thousands, except for per share dollar amounts):

Nonvested Shares	Shares		Weighted Average Grant Date Fair Value
Nonvested at December 31, 2012	397		$	16.72
Granted	391		10.20
Vested	(98	)	19.28
Forfeited	(166	)	11.96
Nonvested at December 31, 2013	524		$	12.88

Employee stock purchase plan weighted-average assumptions

	Year Ended December 31,
	2013			2012			2011
Expected dividends	$	—		$	—		$	—
Stock price on valuation date	7.77			11.96			17.54
Expected volatility	46		%	71		%	41		%
Risk-free interest rate	0.07		%	0.10		%	0.15		%
Expected life (in years)	0.3			0.5			0.5
Fair value per share	$	2.45		$	4.16		$	4.73

Employee service share-based compensation cost

Compensation cost for stock options, restricted stock, restricted stock units and the ESPP is as follows (in thousands):

	Year Ended December 31,
	2013		2012		2011
Stock options	$	827	$	978	$	1,317
Restricted stock	2,491		1,427		1,014
Restricted stock units	592		421		57
ESPP	70		262		194
Total stock-based compensation expense	$	3,980	$	3,088	$	2,582

Stock-based compensation cost included in cost of revenue; selling, general and administrative expense; and research and development expense is as follows (in thousands):

	Year Ended December 31,
	2013		2012		2011
Cost of revenue	$	1,079	$	701	$	355
Selling, general and administrative	2,140		1,835		1,769
Research and development	761		552		458
Total stock-based compensation expense	$	3,980	$	3,088	$	2,582

Reservation of shares for issuance upon exercise, vesting or release of share-based compensation awards

The following table summarizes the reservation of shares under the Company's stock-based compensation plans as of December 31, 2013:

2013 Omnibus Equity Incentive Plan	1,584,994
2004 Employee Stock Purchase Plan	568,336
2005 Omnibus Equity Incentive Plan	1,039,655
1995 Stock Option Plan	32,950
Total	3,225,935