Income Taxes	3 Months Ended
Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We have United States (“U.S.”) federal net operating loss and research and development tax credit carryforwards, as well as state and city net operating loss carryforwards, which may be used to reduce future taxable income and tax liabilities. We also have foreign net operating loss and tax credit carryforwards, and the foreign net operating loss carryforwards do not expire. All of our deferred tax assets have been fully offset by a valuation allowance due to our cumulative losses. The carrying value of our deferred tax assets and liabilities is determined by the enacted U.S. corporate income tax rate. Consequently, any changes in the U.S. corporate income tax rate impacts the carrying value of our deferred tax assets and liabilities. Also, there are significant limitations on our ability to utilize our net operating loss and tax credit carryforwards under Section 382 of the Internal Revenue Code of 1986, as amended.

Income Taxes

3 Months Ended

Mar. 31, 2020

We have United States (“U.S.”) federal net operating loss and research and development tax credit carryforwards, as well as state and city net operating loss carryforwards, which may be used to reduce future taxable income and tax liabilities. We also have foreign net operating loss and tax credit carryforwards, and the foreign net operating loss carryforwards do not expire. All of our deferred tax assets have been fully offset by a valuation allowance due to our cumulative losses. The carrying value of our deferred tax assets and liabilities is determined by the enacted U.S. corporate income tax rate. Consequently, any changes in the U.S. corporate income tax rate impacts the carrying value of our deferred tax assets and liabilities. Also, there are significant limitations on our ability to utilize our net operating loss and tax credit carryforwards under Section 382 of the Internal Revenue Code of 1986, as amended.