Income Taxes	9 Months Ended
Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The Company recorded an income tax provision of $0.2 million for the three months ended September 30, 2018, as compared to $1.2 million for the three months ended September 30, 2017. The Company recorded an income tax provision of $0.5 million income tax provision for the nine months ended September 30, 2018, as compared to an income tax provision of $3.6 million for the nine months ended September 30, 2017. The decreases in the Company’s income tax provision for the three and nine months ended September 30, 2018, relative to the respective prior year periods, were due to lower tax expense in the US as a result of specified provisions in the Tax Cuts and Jobs Act of 2017, including a decrease in the US statutory tax rate from 35% to 21% and changes to the Company’s valuation allowance, and additional foreign research tax credits. The Company regularly evaluates the realizability of its net deferred tax assets based on all available evidence, both positive and negative. The realization of net deferred tax assets is dependent on several factors, including the likelihood and amount, if any, of future taxable income in relevant jurisdictions during periods in which those temporary differences become deductible. As of September 30, 2018, the Company continues to maintain a full valuation allowance on its deferred tax assets that are not realizable on a more likely than not basis. On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the “Tax Act”) was signed into law making significant changes to the U.S. Internal Revenue Code. Changes include, but are not limited to, a federal corporate tax rate decrease from 35% to 21%, effective for tax years beginning after December 31, 2017, the transition of U.S. international taxation from a worldwide tax system to a territorial system, and the creation of a global intangible low-taxed income inclusion (“GILTI”). On December 22, 2017, the SEC issued Staff Accounting Bulletin 118 (“SAB 118”) to address the application of GAAP in situations when a company does not have the necessary information available, prepared, or analyzed in reasonable detail to complete the accounting for certain income tax effects resulting from the Tax Act. Under SAB 118, the Company is allowed a measurement period of up to one year after the enactment date of the Tax Act to finalize the recording of the related tax impacts. As of September 30, 2018, the Company has not yet completed its accounting for the tax effects of the Tax Act nor has it made any significant adjustments to its provisional estimates recorded during the year ended December 31, 2017. The Company will continue its analysis of these provisional amounts, which are still subject to change during the allowable measurement period. The FASB Staff Q&A, Topic 740, No. 5, Accounting for Global Intangible Low-Taxed Income ("GILTI"), states that an entity can make an accounting policy election to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years or provide for the tax expense related to GILTI in the year the tax is incurred as a period expense. Given the complexity of the GILTI provisions, the Company is still evaluating the effects and has not yet determined its accounting policy. As of September 30, 2018, the Company has included GILTI related to current year operations in its estimated annual effective tax rate and has not provided additional GILTI on deferred items. The Company believes that it has provided adequate reserves for its income tax uncertainties in all open tax years. As the outcome of the audits cannot be predicted with certainty, if any issues addressed in the Company's tax audits are resolved in a manner inconsistent with management's expectations, the Company could be required to adjust its provision for income taxes in the period such resolution occurs. There were no material changes in gross unrecognized tax benefits during the three and nine months ended September 30, 2018 and 2017.

10. Income Taxes

The Company recorded an income tax provision of $0.2 million for the three months ended September 30, 2018, as compared to $1.2 million for the three months ended September 30, 2017. The Company recorded an income tax provision of $0.5 million income tax provision for the nine months ended September 30, 2018, as compared to an income tax provision of $3.6 million for the nine months ended September 30, 2017. The decreases in the Company’s income tax provision for the three and nine months ended September 30, 2018, relative to the respective prior year periods, were due to lower tax expense in the US as a result of specified provisions in the Tax Cuts and Jobs Act of 2017, including a decrease in the US statutory tax rate from 35% to 21% and changes to the Company’s valuation allowance, and additional foreign research tax credits.

The Company regularly evaluates the realizability of its net deferred tax assets based on all available evidence, both positive and negative. The realization of net deferred tax assets is dependent on several factors, including the likelihood and amount, if any, of future taxable income in relevant jurisdictions during periods in which those temporary differences become deductible. As of September 30, 2018, the Company continues to maintain a full valuation allowance on its deferred tax assets that are not realizable on a more likely than not basis.

On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the “Tax Act”) was signed into law making significant changes to the U.S. Internal Revenue Code. Changes include, but are not limited to, a federal corporate tax rate decrease from 35% to 21%, effective for tax years beginning after December 31, 2017, the transition of U.S. international taxation from a worldwide tax system to a territorial system, and the creation of a global intangible low-taxed income inclusion (“GILTI”).

On December 22, 2017, the SEC issued Staff Accounting Bulletin 118 (“SAB 118”) to address the application of GAAP in situations when a company does not have the necessary information available, prepared, or analyzed in reasonable detail to complete the accounting for certain income tax effects resulting from the Tax Act. Under SAB 118, the Company is allowed a measurement period of up to one year after the enactment date of the Tax Act to finalize the recording of the related tax impacts. As of September 30, 2018, the Company has not yet completed its accounting for the tax effects of the Tax Act nor has it made any significant adjustments to its provisional estimates recorded during the year ended December 31, 2017. The Company will continue its analysis of these provisional amounts, which are still subject to change during the allowable measurement period.

The FASB Staff Q&A, Topic 740, No. 5, Accounting for Global Intangible Low-Taxed Income ("GILTI"), states that an entity can make an accounting policy election to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years or provide for the tax expense related to GILTI in the year the tax is incurred as a period expense. Given the complexity of the GILTI provisions, the Company is still evaluating the effects and has not yet determined its accounting policy. As of September 30, 2018, the Company has included GILTI related to current year operations in its estimated annual effective tax rate and has not provided additional GILTI on deferred items.

The Company believes that it has provided adequate reserves for its income tax uncertainties in all open tax years. As the outcome of the audits cannot be predicted with certainty, if any issues addressed in the Company's tax audits are resolved in a manner inconsistent with management's expectations, the Company could be required to adjust its provision for income taxes in the period such resolution occurs. There were no material changes in gross unrecognized tax benefits during the three and nine months ended September 30, 2018 and 2017.