Income Taxes

3 Months Ended

Mar. 31, 2019

Income Tax Disclosure [Abstract]

Income Taxes

Income Taxes

We determine our income tax provision for interim periods using an estimate of our annual effective tax rate adjusted for discrete items occurring during the periods presented. The primary difference between our effective tax rate and the federal statutory rate is the full valuation allowance we have established on our federal and state net operating losses and credits. Income taxes from international operations are not material for the three months ended March 31, 2019 and 2018.