Stockholders' Equity, Equity Incentive Plans and Warrants (Tables)

12 Months Ended

Dec. 31, 2012

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

Share-based compensation expense

The following table summarizes share-based compensation expense for the years ended December 31, (in thousands):

	2010		2011		2012
Cost of goods sold	$	489	$	828	$	617
Sales and marketing	333		540		419
Research and development	908		2,200		1,705
General and administrative	819		1,548		1,024
Share-based compensation expense before taxes	2,549		5,116		3,765
Related deferred income tax benefits	—		—		—
Share-based compensation expense	$	2,549	$	5,116	$	3,765
Share-based compensation expense is derived from:
Stock options	$	1,577	$	1,434	$	1,508
Restricted stock awards	610		2,303		1,958
Stock bonus plan	—		1,005		—
2000 ESPP	362		374		299
Total	$	2,549	$	5,116	$	3,765

Summary of stock option activity

A summary of stock option activity is as follows:

	Number of shares		Weighted average exercise price		Weighted average remaining contractual term (in years)	Aggregate intrinsic value
Outstanding at January 1, 2012	7,394,551		$	3.39
Granted	2,486,000		1.36
Exercised	(27,189	)	0.83
Forfeited	(574,705	)	1.84
Expired	(326,528	)	3.53
Outstanding at December 31, 2012	8,952,129		$	2.93	4.56	$	28,380
Vested and expected to vest at December 31, 2012	8,560,457		$	3.00	4.44	$	24,990
Exercisable at December 31, 2012	5,622,274		$	3.67	3.77	$	9,312

Summary of restricted stock activity

A summary of restricted stock award activity for 2012 is as follows:

	Number of shares		Weighted average grant date fair value
Outstanding at January 1, 2012	2,233,563		$	2.09
Granted	843,968		1.23
Vested	(1,915,270	)	1.72
Forfeited	(506,859	)	1.92
Outstanding and unvested at December 31, 2012	655,402		$	2.16

Schedule of valuation assumptions for equity awards

To estimate compensation expense for the years ended December 31, 2010, 2011, and 2012 we used the Black-Scholes option-pricing model with the following weighted-average assumptions for equity awards granted:

	EIP and NEDSOP						ESPP
	Years Ended December 31,						Years Ended December 31,
	2010		2011		2012		2010		2011		2012
Risk-free interest rate	2.25	%	1.84	%	1.19	%	0.19	%	0.17	%	0.12	%
Expected dividend yield	—	%	—	%	—	%	—	%	—	%	—	%
Volatility	74	%	85	%	81	%	101	%	70	%	64	%
Expected Term	5.9 years		5.4 years		5.2 years		0.5 years		0.5 years		0.5 years
Forfeiture Rate	0%-12.69%		0%-12.25%		0%-10.62%		—	%	—	%	—	%