Consolidated Statements of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Treasury Stock	Accumulated Deficit
Beginning Balance, Stockholders' Equity at Dec. 31, 2010	$ 62,655	$ 54	$ 634,944	$ 20,207	$ (37,986)	$ (554,564)
Beginnng Balance, Shares, Outstanding at Dec. 31, 2010		54,440			4,181
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(17,950)					(17,950)
Other comprehensive loss, net of tax	265			265
Shares issued in connection with public offering, net, shares		7,820
Shares issued in connection with public offering, net, value	12,599	9	12,590
Shares issued under employee stock plan, net, shares		144
Shares issued under employee stock plan, net,, value	87		87
Shares issued under employee stock purchase plan, shares		143
Shares issued under employee stock purchase plan, value	185		185
Stock-based compensation expense	2,304		2,304
Ending Balance, Stockholders' Equity at Dec. 31, 2011	60,145	63	650,110	20,472	(37,986)	(572,514)
Ending Balance, Shares, Outstanding at Dec. 31, 2011		62,547			4,181
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(19,319)					(19,319)
Other comprehensive loss, net of tax	535			535
Shares issued under employee stock plan, net, shares		256
Shares issued under employee stock plan, net,, value	238		238
Shares issued under employee stock purchase plan, shares		105
Shares issued under employee stock purchase plan, value	128		128
Stock-based compensation expense	1,565		1,565
Ending Balance, Stockholders' Equity at Dec. 31, 2012	43,292	63	652,041	21,007	(37,986)	(591,833)
Ending Balance, Shares, Outstanding at Dec. 31, 2012		62,908			4,181
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(10,975)					(10,975)
Other comprehensive loss, net of tax	(177)			(177)
Shares issued under employee stock plan, net, shares		413
Shares issued under employee stock plan, net,, value	445		445
Shares issued under employee stock purchase plan, shares		63
Shares issued under employee stock purchase plan, value	131		131
Stock-based compensation expense	1,433		1,433
Ending Balance, Stockholders' Equity at Dec. 31, 2013	$ 34,149	$ 63	$ 654,050	$ 20,830	$ (37,986)	$ (602,808)
Ending Balance, Shares, Outstanding at Dec. 31, 2013		63,384			4,181