Income Taxes	6 Months Ended
Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On December 22, 2017, the U.S. Tax Cuts and Jobs Act (“TCJA”) was enacted reducing the corporate tax rate from 35% to 21% effective for tax years beginning on or after January 1, 2018. ASC 740, Income Taxes, requires the effects of changes in tax laws to be recognized in the period in which the legislation is enacted. However, due to the complexity and significance of TCJA's provisions, the SEC staff issued Staff Accounting Bulletin 118, which allows companies to record the tax effects of the TCJA on a provisional basis based on a reasonable estimate, and then, if necessary, subsequently adjust such amounts during a limited measurement period as more information becomes available. The measurement period ends when a company has obtained, prepared, and analyzed the information necessary to finalize its accounting, but cannot extend beyond one year from enactment of the TCJA. Under the TCJA, the Corporate Alternative Minimum Tax ("AMT") was repealed. The Company's previously recorded AMT credits of approximately $3.5 million are now refundable over a four-year period beginning in 2018, and the previously recorded valuation allowance for these AMT credits was reversed during the fourth quarter of 2017. During the six months ended June 30, 2018, the Company reduced its estimate of refundable AMT credits to approximately $3.3 million to reflect the impact of sequestration as required by the Balanced Budget and Emergency Deficit Control Act of 1985, as amended. As a result of the TCJA’s reduction in the corporate tax rate from 35% to 21% the value of the Company’s deferred tax assets, and related valuation allowance, were reduced by a provisional amount of approximately $54.6 million during the year ended December 31, 2017. The Company does not have any offshore earnings from which to record the mandatory transition tax enacted under the TCJA. Given the significant complexity of the TCJA, anticipated guidance from the US Treasury and the Internal Revenue Service about implementing the TCJA, and the potential for additional guidance from the SEC or the FASB related to the TCJA, the deferred taxes provisional amounts may be adjusted during the measurement period. These provisional amounts were based on the Company’s present interpretations of the TCJA and current available information, including assumptions and expectations about future events, such as its projected financial performance, and are subject to further refinement as additional information becomes available (including potential new interpretative guidance) and further analyses are completed. For the three and six months ended June 30, 2018, the Company recorded a $1.0 million and $0.8 million benefit for income taxes, respectively. The benefit for income taxes recorded during the three months ended June 30, 2018 was to reflect the settlement of a local tax audit. The income tax benefit for the six months ended June 30, 2018 includes the provision for income taxes recorded by the Company for the three months ended March 31, 2018 to reflect the impact of sequestration on the Company's estimate of refundable AMT credits. For the three and six months ended June 30, 2017, the Company recorded a de minimis income tax benefit and provision for income taxes, respectively. The Company will continue to evaluate its ability to realize its deferred tax assets on a quarterly basis and will adjust such amounts in light of changing facts and circumstances including, but not limited to, future projections of taxable income, tax legislation, rulings by relevant tax authorities, the progress of ongoing tax audits and the regulatory approval of products currently under development. Any additional changes to the valuation allowance recorded on deferred tax assets in the future would impact the Company’s income taxes.

Income Taxes

On December 22, 2017, the U.S. Tax Cuts and Jobs Act (“TCJA”) was enacted reducing the corporate tax rate from 35% to 21% effective for tax years beginning on or after January 1, 2018. ASC 740, Income Taxes, requires the effects of changes in tax laws to be recognized in the period in which the legislation is enacted. However, due to the complexity and significance of TCJA's provisions, the SEC staff issued Staff Accounting Bulletin 118, which allows companies to record the tax effects of the TCJA on a provisional basis based on a reasonable estimate, and then, if necessary, subsequently adjust such amounts during a limited measurement period as more information becomes available. The measurement period ends when a company has obtained, prepared, and analyzed the information necessary to finalize its accounting, but cannot extend beyond one year from enactment of the TCJA.

Under the TCJA, the Corporate Alternative Minimum Tax ("AMT") was repealed. The Company's previously recorded AMT credits of approximately $3.5 million are now refundable over a four-year period beginning in 2018, and the previously recorded valuation allowance for these AMT credits was reversed during the fourth quarter of 2017. During the six months ended June 30, 2018, the Company reduced its estimate of refundable AMT credits to approximately $3.3 million to reflect the impact of sequestration as required by the Balanced Budget and Emergency Deficit Control Act of 1985, as amended. As a result of the TCJA’s reduction in the corporate tax rate from 35% to 21% the value of the Company’s deferred tax assets, and related valuation allowance, were reduced by a provisional amount of approximately $54.6 million during the year ended December 31, 2017. The Company does not have any offshore earnings from which to record the mandatory transition tax enacted under the TCJA. Given the significant complexity of the TCJA, anticipated guidance from the US Treasury and the Internal Revenue Service about implementing the TCJA, and the potential for additional guidance from the SEC or the FASB related to the TCJA, the deferred taxes provisional amounts may be adjusted during the measurement period. These provisional amounts were based on the Company’s present interpretations of the TCJA and current available information, including assumptions and expectations about future events, such as its projected financial performance, and are subject to further refinement as additional information becomes available (including potential new interpretative guidance) and further analyses are completed.

For the three and six months ended June 30, 2018, the Company recorded a $1.0 million and $0.8 million benefit for income taxes, respectively. The benefit for income taxes recorded during the three months ended June 30, 2018 was to reflect the settlement of a local tax audit. The income tax benefit for the six months ended June 30, 2018 includes the provision for income taxes recorded by the Company for the three months ended March 31, 2018 to reflect the impact of sequestration on the Company's estimate of refundable AMT credits. For the three and six months ended June 30, 2017, the Company recorded a de minimis income tax benefit and provision for income taxes, respectively.

The Company will continue to evaluate its ability to realize its deferred tax assets on a quarterly basis and will adjust such amounts in light of changing facts and circumstances including, but not limited to, future projections of taxable income, tax legislation, rulings by relevant tax authorities, the progress of ongoing tax audits and the regulatory approval of products currently under development. Any additional changes to the valuation allowance recorded on deferred tax assets in the future would impact the Company’s income taxes.