8.  Income Taxes  

Our income tax benefit for the three months ended March 31, 2016 and 2015 was $4.9 million and $103.6 million, respectively.  Our annualized effective tax rate for the three months ended March 31, 2016 and 2015 was 2.5% and 28.9%, respectively.  Both of these percentages differ from the federal statutory rate of 35.0% primarily due to recording and adjusting a valuation allowance for our deferred tax assets.     

 During the three months ended March 31, 2016 and 2015, we recorded a valuation allowance of $60.0 million and $22.5 million, respectively, related to federal and state deferred tax assets.  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 addition, the realization depends on the ability to carryback certain items to prior years for refunds of taxes previously paid.  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.  As of March 31, 2016 and December 31, 2015, we had a valuation allowance related to Federal, Louisiana and Alabama net operating losses and other deferred taxes.  The tax years 2012 through 2015 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, 2016 and 2015, we recorded immaterial amounts of accrued interest expense related to our unrecognized tax benefit.