Income Taxes	3 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We utilize our estimated annual effective tax rate to determine our provision for income taxes for interim periods. The income tax provision is computed by taking the estimated annual effective rate and multiplying it by the year-to-date pre-tax book income. We recorded an income tax benefit of $0.2 million and $0.3 million for the three months ended March 31, 2018 and 2017, respectively, and our effective tax rate was 22.0% and 168.0% during the three months ended March 31, 2018 and 2017, respectively. The change in our effective tax rate was primarily due to a favorable tax ruling that resulted in the reversal of a $0.2 million reserve during the three months ended March 31, 2017. The Tax Cuts and Jobs Act was enacted on December 22, 2017. The Act reduces the U.S. federal corporate income tax rate from 35% to 21%, requires companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and creates new taxes on certain foreign sourced earnings. We are applying the guidance in SAB 118 when accounting for the enactment-date effects of the Act. At March 31, 2018, we have not completed our accounting for all of the tax effects of the Act. Additionally, we have made a reasonable estimate of other effects. During the three month period ended March 31, 2018, we recognized no adjustments to the provisional amounts recorded at December 31, 2017. We are awaiting further guidance from the U.S. federal and state regulatory bodies with regards to the final accounting and reporting of these items in the several jurisdictions where we file tax returns. In all cases, we will continue to refine our calculations as additional analysis is completed. Our estimates may also be affected as we gain a more thorough understanding of tax law. These changes could be material to income tax expense. Additionally, we have provided provisional amounts for the legislative provisions that are effective as of January 1, 2018, including, but not limited to, the creation of the base erosion anti-abuse tax (BEAT), a new minimum tax, a new provision designed to tax global intangible low-taxed income (Global Minimum Tax, or GMT), a new limitation on deductible interest expense, and limitations on the use of net operating losses. Our accounting for these elements of the Tax Act is incomplete; however, we were able to make reasonable estimates and therefore recorded provisional adjustments. Similar to the above elements, we are in the process of collecting and preparing necessary data, and interpreting guidance as issued by the U.S. Treasury Department, Internal Revenue Service ("IRS"), FASB, and other federal and state standard-setting regulatory bodies. However, we continue to gather additional information to complete our accounting for these items and expect to complete the accounting within the prescribed measurement period. Given the complexity of the GMT provisions, we are still evaluating the effects of the GMT provisions and have not yet determined our accounting policy. At March 31, 2018, we are still evaluating the GMT provisions and our analysis of future taxable income that is subject to GMT, we have included GMT related to current year operations only in our estimated annual effective tax rate and have not provided additional GMT on deferred items. At March 31, 2018, we had gross unrecognized tax benefits of $5.7 million, including interest and penalties, of which approximately $5.3 million, if not for the state Research and Experimentation income tax credit valuation allowance, would affect the annual effective tax rate if these tax benefits are realized. Further, we are unaware of any positions for which it is reasonably possible that the total amount of unrecognized tax benefits will significantly change within the next twelve months. Based on federal, state and foreign statute expirations in various jurisdictions, we do not anticipate any decrease in unrecognized tax benefits within the next twelve months. We have classified uncertain tax positions as non-current income tax liabilities unless expected to be paid within one year. We have elected to classify interest and penalties as a component of tax expense. Accrued interest and penalties of $0.6 million and $0.5 million at March 31, 2018 and December 31, 2017, respectively, are included in our unrecognized tax benefits.

Income Taxes

We utilize our estimated annual effective tax rate to determine our provision for income taxes for interim periods. The income tax provision is computed by taking the estimated annual effective rate and multiplying it by the year-to-date pre-tax book income.

We recorded an income tax benefit of $0.2 million and $0.3 million for the three months ended March 31, 2018 and 2017, respectively, and our effective tax rate was 22.0% and 168.0% during the three months ended March 31, 2018 and 2017, respectively. The change in our effective tax rate was primarily due to a favorable tax ruling that resulted in the reversal of a $0.2 million reserve during the three months ended March 31, 2017.

The Tax Cuts and Jobs Act was enacted on December 22, 2017. The Act reduces the U.S. federal corporate income tax rate from 35% to 21%, requires companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and creates new taxes on certain foreign sourced earnings. We are applying the guidance in SAB 118 when accounting for the enactment-date effects of the Act. At March 31, 2018, we have not completed our accounting for all of the tax effects of the Act. Additionally, we have made a reasonable estimate of other effects. During the three month period ended March 31, 2018, we recognized no adjustments to the provisional amounts recorded at December 31, 2017. We are awaiting further guidance from the U.S. federal and state regulatory bodies with regards to the final accounting and reporting of these items in the several jurisdictions where we file tax returns. In all cases, we will continue to refine our calculations as additional analysis is completed. Our estimates may also be affected as we gain a more thorough understanding of tax law. These changes could be material to income tax expense.

Additionally, we have provided provisional amounts for the legislative provisions that are effective as of January 1, 2018, including, but not limited to, the creation of the base erosion anti-abuse tax (BEAT), a new minimum tax, a new provision designed to tax global intangible low-taxed income (Global Minimum Tax, or GMT), a new limitation on deductible interest expense, and limitations on the use of net operating losses. Our accounting for these elements of the Tax Act is incomplete; however, we were able to make reasonable estimates and therefore recorded provisional adjustments. Similar to the above elements, we are in the process of collecting and preparing necessary data, and interpreting guidance as issued by the U.S. Treasury Department, Internal Revenue Service ("IRS"), FASB, and other federal and state standard-setting regulatory bodies. However, we continue to gather additional information to complete our accounting for these items and expect to complete the accounting within the prescribed measurement period. Given the complexity of the GMT provisions, we are still evaluating the effects of the GMT provisions and have not yet determined our accounting policy. At March 31, 2018, we are still evaluating the GMT provisions and our analysis of future taxable income that is subject to GMT, we have included GMT related to current year operations only in our estimated annual effective tax rate and have not provided additional GMT on deferred items.

At March 31, 2018, we had gross unrecognized tax benefits of $5.7 million, including interest and penalties, of which approximately $5.3 million, if not for the state Research and Experimentation income tax credit valuation allowance, would affect the annual effective tax rate if these tax benefits are realized. Further, we are unaware of any positions for which it is reasonably possible that the total amount of unrecognized tax benefits will significantly change within the next twelve months. Based on federal, state and foreign statute expirations in various jurisdictions, we do not anticipate any decrease in unrecognized tax benefits within the next twelve months. We have classified uncertain tax positions as non-current income tax liabilities unless expected to be paid within one year.

We have elected to classify interest and penalties as a component of tax expense. Accrued interest and penalties of $0.6 million and $0.5 million at March 31, 2018 and December 31, 2017, respectively, are included in our unrecognized tax benefits.