Income Taxes (Details Textuals) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 12 Months Ended
Mar. 31, 2012
Dec. 31, 2011
Mar. 31, 2011
Feb. 28, 2011
Operating Loss Carryforwards [Line Items]        
Federal and state net operating loss carry-forwards     $ 675 $ 703
Federal research and experimentation tax credit carry-forwards expire prior to utilization     618.0  
Net Unrealized Built in Losses per IRS Notice 2003-65   7    
Income tax losses recognized period   5 years    
Gross deferred tax liability   1.8 2.6  
Percentage of change in ownership 5.00%      
Federal and state net operating loss carry-forwards not expiring prior to utilization 14.9      
Gross deferred tax asset and related valuation allowance decrease 24.6      
Losses during the five year recognition period 34.0      
Potential recognized deferred income tax liabilities if ownership changed per IRC Section 382 12.9      
Research Tax Credit Carryforward
        
Operating Loss Carryforwards [Line Items]        
Federal research and experimentation tax credit carry-forwards expire prior to utilization       15.6
Federal research and experimentation tax credit carry-forwards expire prior to utilization     $ 15.6