Income Taxes	3 Months Ended
Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company’s effective tax rate is approximately 5% and 0% for the three-month periods ended March 31, 2020 and 2019, respectively. The Company's effective tax rate differs from the statutory federal tax rate of 21% for the three month period ended March 31, 2020 primarily due to a full valuation allowance recorded on our United States, China and Italy deferred tax assets since we cannot anticipate when or if we will have sufficient taxable income to utilize the deferred tax assets in the future. Further, our effective tax rate differs from the statutory federal tax rate due to state taxes, differences between U.S. and foreign tax rates, foreign losses incurred with no related tax benefit, non-deductible commissions, and non-deductible meals and entertainment expenses for the three month periods ended March 31, 2020 and 2019. On April 3, 2019, the Company received notice from the Internal Revenue Service that our U.S. income tax return for the year ended December 31, 2016 is currently under audit. Fuel Tech had no unrecognized tax benefits as of March 31, 2020 and December 31, 2019. On March 27, 2020, President Trump signed into law the Coronavirus Aid, Relief, and Economic Security Act (H.R. 748) (the “CARES Act”). Among the changes to the U.S. federal income tax rules, the Cares Act restored net operating loss carryback rules that were eliminated by 2017 Tax Cuts and Jobs Act, restored 100 percent bonus depreciation for qualified improvement property, modified the limit on the deduction for net interest expense and accelerated the timeframe for refunds of AMT credits. At this time we do not anticipate a material impact to the Company’s current or deferred income taxes as a result of the CARES Act. We will continue to evaluate the effects of the CARES Act as additional legislative guidance become available.

Income Taxes

The Company’s effective tax rate is approximately 5% and 0% for the three-month periods ended March 31, 2020 and 2019, respectively. The Company's effective tax rate differs from the statutory federal tax rate of 21% for the three month period ended March 31, 2020 primarily due to a full valuation allowance recorded on our United States, China and Italy deferred tax assets since we cannot anticipate when or if we will have sufficient taxable income to utilize the deferred tax assets in the future. Further, our effective tax rate differs from the statutory federal tax rate due to state taxes, differences between U.S. and foreign tax rates, foreign losses incurred with no related tax benefit, non-deductible commissions, and non-deductible meals and entertainment expenses for the three month periods ended March 31, 2020 and 2019.

On April 3, 2019, the Company received notice from the Internal Revenue Service that our U.S. income tax return for the year ended December 31, 2016 is currently under audit.

Fuel Tech had no unrecognized tax benefits as of March 31, 2020 and December 31, 2019.

On March 27, 2020, President Trump signed into law the Coronavirus Aid, Relief, and Economic Security Act (H.R. 748) (the “CARES Act”). Among the changes to the U.S. federal income tax rules, the Cares Act restored net operating loss carryback rules that were eliminated by 2017 Tax Cuts and Jobs Act, restored 100 percent bonus depreciation for qualified improvement property, modified the limit on the deduction for net interest expense and accelerated the timeframe for refunds of AMT credits. At this time we do not anticipate a material impact to the Company’s current or deferred income taxes as a result of the CARES Act. We will continue to evaluate the effects of the CARES Act as additional legislative guidance become available.