Income Taxes	3 Months Ended
Mar. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	11. Income Taxes Tax provisions for interim periods are calculated using an estimate of actual taxable income or loss for the respective period, rather than estimating the Company’s annual effective income tax rate, as the Company is currently unable to reliably estimate its income for the full year. For the three months ended March 31, 2014, the Company had taxable income of approximately $15,300, which, after offset by available loss carryforwards, resulted in $306 of current tax expense due to the corporate alternative minimum tax. The associated deferred tax asset is offset by a valuation allowance due to the Company’s history of net losses combined with an inability to confirm recovery of the tax benefits of the Company’s losses and other net deferred tax assets. For the three months ended March 31, 2013, there is no income tax benefit recognized. In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in making this assessment. Due to the Company’s history of net losses incurred from inception, no deferred income tax benefit has been recorded and the corresponding deferred tax assets have been fully reserved as the Company cannot sufficiently be assured that these deferred tax assets will be realized. At March 31, 2014, the Company has loss carryforwards for federal income tax purposes of approximately $235,400 available to offset future taxable income and federal and state research and development tax credits of approximately $7,000, prior to consideration of annual limitations that may be imposed under Section 382. These carryforwards will begin to expire in 2022. Of these loss carryforwards, approximately $4,300 relate to benefits from stock compensation deductions that will be recorded as a component of paid-in capital when realized.

Income Taxes

3 Months Ended

Mar. 31, 2014

11. Income Taxes

Tax provisions for interim periods are calculated using an estimate of actual taxable income or loss for the respective period, rather than estimating the Company’s annual effective income tax rate, as the Company is currently unable to reliably estimate its income for the full year. For the three months ended March 31, 2014, the Company had taxable income of approximately $15,300, which, after offset by available loss carryforwards, resulted in $306 of current tax expense due to the corporate alternative minimum tax. The associated deferred tax asset is offset by a valuation allowance due to the Company’s history of net losses combined with an inability to confirm recovery of the tax benefits of the Company’s losses and other net deferred tax assets. For the three months ended March 31, 2013, there is no income tax benefit recognized. In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in making this assessment. Due to the Company’s history of net losses incurred from inception, no deferred income tax benefit has been recorded and the corresponding deferred tax assets have been fully reserved as the Company cannot sufficiently be assured that these deferred tax assets will be realized.

At March 31, 2014, the Company has loss carryforwards for federal income tax purposes of approximately $235,400 available to offset future taxable income and federal and state research and development tax credits of approximately $7,000, prior to consideration of annual limitations that may be imposed under Section 382. These carryforwards will begin to expire in 2022. Of these loss carryforwards, approximately $4,300 relate to benefits from stock compensation deductions that will be recorded as a component of paid-in capital when realized.