Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant-date fair value of options granted (in dollars per share)	$ 3.07	$ 4.77
Total Intrinsic Value of options exercised		$ 20
Total Intrinsic Value of options outstanding	$ 15
Total Intrinsic Value of options exercisable	15
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	15
Total unrecognized compensation	$ 4,800
Weighted average periods	2 years 10 months 24 days
Assumptions used in computing the fair value [Abstract]
Risk-free interest rate	1.55%	1.91%
Expected life (in years)	6 years 8 months 16 days	6 years 8 months 16 days
Expected volatility	75.00%	81.00%
Expected dividend yield	0.00%	0.00%
Options, Outstanding [Roll Forward]
Outstanding - beginning balance	5,134,000
Granted	927,000
Exercised	0
Cancelled	(126,000)
Expired	(62,000)
Outstanding - ending balance	5,873,000		5,134,000
Exercisable	4,051,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number	5,492,000
Weighted Average Exercise Price [Roll Forward]
Outstanding - beginning balance (in dollars per share)	$ 9.05
Granted (in dollars per share)	4.52
Exercised (in dollars per share)	0
Cancelled (in dollars per share)	6.11
Expired (in dollars per share)	27.66
Outstanding - ending balance (in dollars per share)	8.20		$ 9.05
Exercisable (in dollars per share)	9.46
Vested and expected to vest (in dollars per share)	$ 8.39
Weighted Average Remaining Contractual Term [Abstract]
Options Outstanding	6 years 3 months 4 days		5 years 8 months 8 days
Options Exercisable	4 years 10 months 28 days
Vested and expected to vest	6 years 11 days
1996 Amended Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance of awards (in shares)	5,000,000
2005 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance of awards (in shares)	11,450,000