Income Taxes (Notes)

3 Months Ended

Mar. 31, 2017

Income Taxes [Abstract]

Income Taxes

Income Taxes

Under ASC 740, Income Taxes (“ASC 740”), companies are required to apply an estimated annual tax rate to interim period results on a year-to-date basis; however, the estimated annual tax rate should not be applied to interim financial results if a reliable estimate cannot be made.  In this situation, the interim tax rate should be based on actual year-to-date results.  Based on our current projections, which have fluctuated as a result of changes in crude oil prices and the related crack spreads, we believe that using actual year-to-date results to compute our effective tax rate will produce a more reliable estimate of our tax expense or benefit.  As such, we recorded a tax provision for the three months ended March 31, 2017 and 2016 based on actual year-to-date results, in accordance with ASC 740.

Our effective tax rate was 24.6% for the three months ended March 31, 2017, compared to 52.3% for the three months ended March 31, 2016. The decrease in our effective tax rate in the three months ended March 31, 2017 was primarily due to the expiration of provisions for certain tax credits and incentives that expired as of December 31, 2016 and have not been extended by Congress, as well as the impact of pre-tax income in the three months ended March 31, 2017, compared to a pre-tax loss in the three months ended March 31, 2016.