Consolidated Statements Of Stockholders' Equity (USD $) In Thousands, except Share data	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Deficit [Member]	Total
Balances at Dec. 31, 2008	$ 301	$ 125,074	$ 693	$ (122,660)	$ 3,408
Balance, Shares at Dec. 31, 2008	30,088,390
Common stock issued, Amount	32	62,396			62,428
Common stock issued, Shares	3,162,500
Upon exercise of stock options and warrants, Amount	5	3,820			3,825
Upon exercise of stock options and warrants, Shares	553,006
Upon vesting of restricted stock units, Shares	19,166
Offering expenses		(369)			(369)
Stock-based compensation expense		10,726			10,726
Excess tax benefit from employee stock plan awards		714			714
Net loss				(54,753)	(54,753)
Change in unrealized gain (loss) on available-for-sale securities			(705)		(705)
Comprehensive loss					(55,458)
Balance at Dec. 31, 2009	338	202,361	(12)	(177,413)	25,274
Ending Balance, Shares at Dec. 31, 2009	33,823,062
Upon exercise of stock options and warrants, Amount	8	2,617			2,625
Upon exercise of stock options and warrants, Shares	740,767
Upon vesting of restricted stock units, Shares	10,000
Stock-based compensation expense		13,530			13,530
Excess tax benefit from employee stock plan awards		278			278
Net loss				(34,037)	(34,037)
Change in unrealized gain (loss) on available-for-sale securities			14		14
Comprehensive loss					(34,023)
Balance at Dec. 31, 2010	346	218,786	2	(211,450)	7,684
Ending Balance, Shares at Dec. 31, 2010	34,573,829				34,573,829
Upon exercise of stock options and warrants, Amount	11	15,723			15,734
Upon exercise of stock options and warrants, Shares	1,106,403				1,106,403
Upon vesting of restricted stock units, Shares	51,606
Stock-based compensation expense		13,774			13,774
Net proceeds from stockholder securities law settlement		2,959			2,959
Net loss				(38,841)	(38,841)
Change in unrealized gain (loss) on available-for-sale securities			11		11
Comprehensive loss					(38,830)
Balance at Dec. 31, 2011	$ 357	$ 251,242	$ 13	$ (250,291)	$ 1,321
Ending Balance, Shares at Dec. 31, 2011	35,731,838				35,731,838