Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
Income tax provision (benefit)	$ (133)	$ (989)	$ (362)
Deferred tax assets and liabilities [Abstract]
Depreciation and amortization	2,215	5,770
R&E tax credit carry-forwards	19,284	18,612
NYS investment tax credit carry-forwards	1,087	1,090
AMT credit carry-forwards	211	211
Net operating loss carry-forwards	226,639	205,792
Capitalized research and development expenditures	15,149	20,280
Stock compensation	12,250	13,848
Other items	2,562	0
Total gross deferred tax assets	279,397	265,603
Less: Valuation allowance	(279,397)	(265,603)
Deferred tax assets:	0	0
Deferred tax liability	(11,199)	(11,332)
Net deferred tax liability	$ (11,199)	$ (11,332)
Reconciliation of income taxes computed at the Federal statutory income tax rate to the actual effective income tax [Abstract]
U.S. Federal statutory rate	34.00%	34.00%	34.00%
State income taxes, net of Federal benefit	4.80%	8.00%	5.40%
Foreign rate differential	(0.10%)	0.00%	0.00%
Research and experimental tax credit	1.70%	(16.00%)	3.80%
Effect of federal and state tax rate changes	(4.80%)	1.60%	(8.70%)
Permanent differences	(1.40%)	15.10%	0.10%
Stock option shortfalls	(6.10%)	38.10%	(3.80%)
New York NOL adjustment	3.80%	0.00%	0.00%
Change in valuation allowance	(31.60%)	(109.60%)	(30.00%)
Income tax benefit	0.30%	(28.80%)	0.80%
Net operating loss carryforwards - federal	$ 606,400
Net operating loss carryforwards - state	554,800
Net operating loss carry-forwards not reflected in deferred tax assets	18,200
Valuation allowance related to net operating loss carryforwards attributable to excess tax deductions for equity compensation	11,000
Deferred tax liability	11,199	$ 11,332
Tax Credit Carryforward, Amount	20,000
Income Taxes [Abstract]
Beginning uncertain tax benefits	2,661	2,661
Current year - increases	0	0
Current year - decreases	0	0
Settlements	0	0
Expired statuses	0	0
Ending uncertain tax benefits	$ 2,661	$ 2,661	$ 2,661