Income Taxes	3 Months Ended
Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On a quarterly basis, the Company computes an estimated annual effective tax rate considering ordinary income and related income tax expense. Ordinary income refers to income (loss) before income tax expense excluding significant, unusual or infrequently occurring items. The tax effect of an unusual or infrequently occurring item is recorded in the interim period in which it occurs. The Company has assessed the need to maintain a valuation allowance for deferred tax assets based on an assessment of whether it is more likely than not that deferred tax benefits will be realized through the generation of future taxable income. Appropriate consideration is given to all available evidence, both positive and negative, in assessing the need for a valuation allowance. In assessing the realizability of the Company’s deferred tax assets, the Company considered whether it is more likely than not that some or all of the deferred tax assets will be realized through the generation of future taxable income. In making this determination, the Company assessed all of the evidence available at the time, including recent earnings, forecasted income projections and historical performance. The Company determined that the negative evidence outweighed the objectively verifiable positive evidence and continues to maintain a full valuation allowance against deferred tax assets. The effective tax rate for the three months ended March 31, 2019 was 18.5%, compared to an effective tax rate for the three months ended March 31, 2018 of 1.9%. The effective tax rates for both periods were significantly different than the applicable U.S. statutory tax rate primarily due to the Company’s full valuation allowance and the impact of the fair value adjustments related to the Weichai Warrant. The effective rate in both periods was also impacted by the increase in the deferred tax liability related to indefinite-lived assets which cannot serve as a source of income for the realization of deferred tax assets and states that base tax on gross margin and not pretax income. Coronovirus Aid, Relief, and Economic Security Act On March 27, 2020, President Trump signed into law the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”). Among the changes to the U.S. federal income tax rules, the CARES Act modified net operating loss carryback rules that were eliminated by the 2017 Tax Cuts and Jobs Act, restored 100% bonus depreciation for qualified improvement property, increased the limit on the deduction for net interest expense and accelerated the time frame for refunds of alternative minimum tax credits. The Company’s ability to carryback the net operating losses to earlier years is expected to result in a tax benefit of $0.8 million. There is no net impact to the Company’s deferred tax assets due to the full valuation allowance. The Company will continue to evaluate the effects of the CARES Act as additional legislative guidance becomes available.

Income Taxes

On a quarterly basis, the Company computes an estimated annual effective tax rate considering ordinary income and related income tax expense. Ordinary income refers to income (loss) before income tax expense excluding significant, unusual or infrequently occurring items. The tax effect of an unusual or infrequently occurring item is recorded in the interim period in which it occurs.

The Company has assessed the need to maintain a valuation allowance for deferred tax assets based on an assessment of whether it is more likely than not that deferred tax benefits will be realized through the generation of future taxable income. Appropriate consideration is given to all available evidence, both positive and negative, in assessing the need for a valuation allowance. In assessing the realizability of the Company’s deferred tax assets, the Company considered whether it is more likely than not that some or all of the deferred tax assets will be realized through the generation of future taxable income. In making this determination, the Company assessed all of the evidence available at the time, including recent earnings, forecasted income projections and historical performance. The Company determined that the negative evidence outweighed the objectively verifiable positive evidence and continues to maintain a full valuation allowance against deferred tax assets.

The effective tax rate for the three months ended March 31, 2019 was 18.5%, compared to an effective tax rate for the three months ended March 31, 2018 of 1.9%. The effective tax rates for both periods were significantly different than the applicable U.S. statutory tax rate primarily due to the Company’s full valuation allowance and the impact of the fair value adjustments related to the Weichai Warrant. The effective rate in both periods was also impacted by the increase in the deferred tax liability related to indefinite-lived assets which cannot serve as a source of income for the realization of deferred tax assets and states that base tax on gross margin and not pretax income.

Coronovirus Aid, Relief, and Economic Security Act

On March 27, 2020, President Trump signed into law the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”). Among the changes to the U.S. federal income tax rules, the CARES Act modified net operating loss carryback rules that were eliminated by the 2017 Tax Cuts and Jobs Act, restored 100% bonus depreciation for qualified improvement property, increased the limit on the deduction for net interest expense and accelerated the time frame for refunds of alternative minimum tax credits. The Company’s ability to carryback the net operating losses to earlier years is expected to result in a tax benefit of $0.8 million. There is no net impact to the Company’s deferred tax assets due to the full valuation allowance. The Company will continue to evaluate the effects of the CARES Act as additional legislative guidance becomes available.