8.  Income Taxes  

Income tax benefit was $103.6 million and income tax expense was $6.6 million for the three months ended March 31, 2015 and 2014, respectively.  Our annualized effective tax rate of 28.9% for the three months ended March 31, 2015 differs from the federal statutory rate of 35% due to the effect of a valuation allowance for our deferred tax assets.  Our effective tax rate for the three months ended March 31, 2014 was 37.3% and differed from the federal statutory rate of 35.0% primarily as a result of state income taxes and other permanent items.  

During the quarter ended March 31, 2015, we recorded a valuation allowance of $22.5 million related to federal deferred tax assets and net operating losses. Additionally, as of March 31, 2015 and December 31, 2014, we had a valuation allowance related to Louisiana state net operating losses. Deferred tax assets are recorded related to net operating losses and temporary differences between the book and tax basis of assets and liabilities expected to produce tax deductions in future periods. The realization of these assets depends on recognition of sufficient future taxable income in specific tax jurisdictions in which those temporary differences or net operating losses are deductible.  In assessing the need for a valuation allowance on our deferred tax assets, we consider whether it is more likely than not that some portion or all of them will not be realized.  The tax years from 2010 through 2014 remain open to examination by the tax jurisdictions to which we are subject.  

We recognize interest and penalties related to unrecognized tax benefits in income tax expense.  During the three months ended March 31, 2015 and 2014, we recorded immaterial amounts of accrued interest expense related to our unrecognized tax benefit.