Income Taxes

6 Months Ended

Jun. 30, 2011

Income Taxes [Abstract]

Income Taxes

9.   Income Taxes

For the three and six months ended June 30, 2011 and 2010, the Company incurred net losses for tax purposes and recognized a full valuation allowance against deferred tax assets.  For the three and six months ended June 30, 2011, the Company recognized an income tax benefit of $0.9 million and $1.1 million, respectively, in connection with the net tax effect of the decrease in the Company's unrealized loss on "available-for-sale" marketable securities, which is included in other comprehensive loss.  For the three and six months ended June 30, 2010, no provision or benefit for income taxes was recorded.