Income Taxes	3 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period during which such rates are enacted. The Company considers all available evidence to determine whether it is more likely than not that some portion or all of the deferred tax assets will 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 realizable. Management considers the scheduled reversal of deferred tax liabilities (including the impact of available carryback and carry-forward periods), and projected taxable income in assessing the realizability of deferred tax assets. In making such judgments, significant weight is given to evidence that can be objectively verified. Based on all available evidence, in particular the Company’s three-year historical cumulative losses, recent operating losses and U.S. pre-tax loss for the three months ended March 31, 2018, the Company recorded a valuation allowance against its U.S. net deferred tax assets. In order to fully realize the U.S. deferred tax assets, the Company will need to generate sufficient taxable income in future periods before the expiration of the deferred tax assets governed by the tax code. In each period since inception, the Company has recorded a valuation allowance for the full amount of net deferred tax assets in the US, as the realization of deferred tax assets is uncertain. ACM Shanghai has shown a three-year historical cumulative profit and has projections of future income. As a result, the Company maintained a partial consolidated valuation allowance for the three months ended March 31, 2018 and December 31, 2017. The Company accounts for uncertain tax positions in accordance with the authoritative guidance on income taxes under which the Company may only recognize or continue to recognize tax positions that meet a "more likely than not" threshold. The Company recognizes accrued interest and penalties related to unrecognized tax benefits as a component of the provision for income taxes. The Company’s effective tax rate differs from statutory rates of 21% for U.S. federal income tax purposes and 15% to 25% for Chinese income tax purposes due to the effects of the valuation allowance and certain permanent differences from book-tax differences. As a result, the Company recorded a tax provision of $22 and $781 for the three months ended March 31, 2018 and 2017, respectively. As of March 31, 2018, the Company's total unrecognized tax benefits were approximately $44, which would not affect the effective tax rate if recognized. The Company will recognize interest and penalties, when they occur, related to uncertain tax provisions as a component of tax expense. No interest or penalties were recognized for the three months ended March 31, 2018. The Company files income tax returns in the United States, and state and foreign jurisdictions. The federal, state and foreign income tax returns are under the statute of limitations subject to tax examinations for the tax years ended December 31, 2009 through December 31, 2017. To the extent the Company has tax attribute carry-forwards, the tax years in which the attribute was generated may still be adjusted upon examination by the U.S. Internal Revenue Service, state or foreign tax authorities to the extent utilized in a future period. The Tax Cuts and Jobs Act (the “Tax Act”) enacted on December 22, 2017 introduced significant changes to U.S. income tax law. Effective January 1, 2018, the Tax Act reduced the U.S. statutory tax rate from 35% to 21% and created new taxes on certain foreign-sourced earnings and certain intercompany payments. Due to the timing of the enactment and the complexity involved in applying the provisions of the Tax Act, the Company made reasonable estimates of the effects and recorded provisional amounts in its financial statements as of December 31, 2017. As the Company collects and prepares necessary data, and interprets the Tax Act and any additional guidance issued by the U.S. Treasury Department, the U.S. Internal Revenue Service and other standard-setting bodies, the Company may make adjustments to the provisional amounts. Those adjustments may materially affect the Company’s provision for income taxes and effective tax rate in the period in which the adjustments are made. There were no adjustments made in the three months ended March 31, 2018. The accounting for the tax effects of the Tax Act will be completed later in 2018.

Income Taxes

3 Months Ended

Mar. 31, 2018

Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period during which such rates are enacted.

The Company considers all available evidence to determine whether it is more likely than not that some portion or all of the deferred tax assets will 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 realizable. Management considers the scheduled reversal of deferred tax liabilities (including the impact of available carryback and carry-forward periods), and projected taxable income in assessing the realizability of deferred tax assets. In making such judgments, significant weight is given to evidence that can be objectively verified. Based on all available evidence, in particular the Company’s three-year historical cumulative losses, recent operating losses and U.S. pre-tax loss for the three months ended March 31, 2018, the Company recorded a valuation allowance against its U.S. net deferred tax assets. In order to fully realize the U.S. deferred tax assets, the Company will need to generate sufficient taxable income in future periods before the expiration of the deferred tax assets governed by the tax code.

In each period since inception, the Company has recorded a valuation allowance for the full amount of net deferred tax assets in the US, as the realization of deferred tax assets is uncertain. ACM Shanghai has shown a three-year historical cumulative profit and has projections of future income. As a result, the Company maintained a partial consolidated valuation allowance for the three months ended March 31, 2018 and December 31, 2017.

The Company accounts for uncertain tax positions in accordance with the authoritative guidance on income taxes under which the Company may only recognize or continue to recognize tax positions that meet a "more likely than not" threshold. The Company recognizes accrued interest and penalties related to unrecognized tax benefits as a component of the provision for income taxes.

The Company’s effective tax rate differs from statutory rates of 21% for U.S. federal income tax purposes and 15% to 25% for Chinese income tax purposes due to the effects of the valuation allowance and certain permanent differences from book-tax differences. As a result, the Company recorded a tax provision of $22 and $781 for the three months ended March 31, 2018 and 2017, respectively.

As of March 31, 2018, the Company's total unrecognized tax benefits were approximately $44, which would not affect the effective tax rate if recognized. The Company will recognize interest and penalties, when they occur, related to uncertain tax provisions as a component of tax expense. No interest or penalties were recognized for the three months ended March 31, 2018.

The Company files income tax returns in the United States, and state and foreign jurisdictions. The federal, state and foreign income tax returns are under the statute of limitations subject to tax examinations for the tax years ended December 31, 2009 through December 31, 2017. To the extent the Company has tax attribute carry-forwards, the tax years in which the attribute was generated may still be adjusted upon examination by the U.S. Internal Revenue Service, state or foreign tax authorities to the extent utilized in a future period. The Tax Cuts and Jobs Act (the “Tax Act”) enacted on December 22, 2017 introduced significant changes to U.S. income tax law. Effective January 1, 2018, the Tax Act reduced the U.S. statutory tax rate from 35% to 21% and created new taxes on certain foreign-sourced earnings and certain intercompany payments. Due to the timing of the enactment and the complexity involved in applying the provisions of the Tax Act, the Company made reasonable estimates of the effects and recorded provisional amounts in its financial statements as of December 31, 2017. As the Company collects and prepares necessary data, and interprets the Tax Act and any additional guidance issued by the U.S. Treasury Department, the U.S. Internal Revenue Service and other standard-setting bodies, the Company may make adjustments to the provisional amounts. Those adjustments may materially affect the Company’s provision for income taxes and effective tax rate in the period in which the adjustments are made. There were no adjustments made in the three months ended March 31, 2018. The accounting for the tax effects of the Tax Act will be completed later in 2018.