Income taxes	6 Months Ended
Jun. 30, 2019
Income taxes
Income taxes	13. Income taxes Income tax benefit of $81 and income tax expense of $(16) reflect effective tax rates of 54.7% and (0.6)% for the three months ended June 30, 2019 and 2018, respectively. Income tax expense of $(111) and $(144) reflect effective tax rates of (2.3)% and (121.0)% for the six months ended June 30, 2019 and 2018, respectively. Our effective tax rate differs from the statutory rate primarily due to our valuation allowance for the three and six months ended June 30, 2019 and 2018 as well as foreign tax expense for the three and six months ended June 30, 2018. We operate within federal, state and international taxing jurisdictions and are subject to audit in these jurisdictions. These audits can involve complex issues which may require an extended period to resolve. We are subject to taxation in the United States and in various states. Our tax years 2016 and forward are subject to examination by the IRS and our tax years 2014 and forward are subject to examination by material state jurisdictions. However, due to prior year loss carryovers, the IRS and state tax authorities may examine any tax years for which the carryovers are used to offset future taxable income.

Income taxes

6 Months Ended

Jun. 30, 2019

13. Income taxes

Income tax benefit of $81 and income tax expense of $(16) reflect effective tax rates of 54.7% and (0.6)% for the three months ended June 30, 2019 and 2018, respectively. Income tax expense of $(111) and $(144) reflect effective tax rates of (2.3)% and (121.0)% for the six months ended June 30, 2019 and 2018, respectively. Our effective tax rate differs from the statutory rate primarily due to our valuation allowance for the three and six months ended June 30, 2019 and 2018 as well as foreign tax expense for the three and six months ended June 30, 2018.

We operate within federal, state and international taxing jurisdictions and are subject to audit in these jurisdictions. These audits can involve complex issues which may require an extended period to resolve. We are subject to taxation in the United States and in various states. Our tax years 2016 and forward are subject to examination by the IRS and our tax years 2014 and forward are subject to examination by material state jurisdictions. However, due to prior year loss carryovers, the IRS and state tax authorities may examine any tax years for which the carryovers are used to offset future taxable income.