Income Taxes (Notes)

6 Months Ended

Jun. 30, 2017

Income taxes recorded through June 30, 2017 and 2016, were estimated using the discrete method. Income taxes are based on our financial results through the end of the period, as well as the related change in the valuation allowance on deferred tax assets. We are unable to estimate the annual effective tax rate with sufficient precision for purposes of the effective tax rate method, which requires us to consider a projection of full-year income and the expected change in the valuation allowance. The estimated annual effective tax rate method was not reliable due to its sensitivity to small changes to forecasted annual pre-tax earnings and the effect of our valuation allowance, which create results with significant variations in the customary relationship between income tax expense and pre-tax income for the interim periods. As a result, we determined that using the discrete method is more appropriate than using the annual effective tax rate method. We have estimated the change in valuation allowances required based on our year-to-date financial results and the change in value of the identified tax-planning strategy, which is determined based on year-to-date changes in the LIFO reserve. In addition, the change in valuation allowance for the six months ended June 30, 2016 includes a $4.4 benefit related to the realizability of certain alternative minimum tax credits.