8.  Income Taxes  

Income tax expense of $0.9 million and $12.8 million was recorded during the three and nine months ended September 30, 2014, respectively.  Our effective tax rate for the three months ended September 30, 2014 was not meaningful due to adjustments for a revised estimated effective tax rate computed on a year-to-date basis.  Our effective tax rate for the nine months ended September 30, 2014 was 37.1%.  The rate for the nine months ended September 30, 2014 differed from the federal statutory rate of 35.0% primarily as a result of state income taxes and other permanent items.  Income tax expense of $8.0 million and $35.4 million was recorded during the three and nine months ended September 30, 2013, respectively.  The effective tax rate for the three and nine months ended September 30, 2013 was 36.1% and 35.9%, respectively, and differed from the federal statutory rate primarily as a result of state income taxes.

During the nine months ended September 30, 2014, we received $3.0 million of refunds.  During 2013, we received refunds of $59.1 million, of which $9.5 million of these refunds have been accounted for as unrecognized tax benefits.  We recognize interest and penalties related to unrecognized tax benefits in income tax expense.  During the three and nine months ended September 30, 2014 and 2013, we recorded immaterial amounts of accrued interest expense related to our unrecognized tax benefit.  As of September 30, 2014 and December 31, 2013, we had a valuation allowance related to state net operating losses.  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.  The tax years from 2010 through 2013 remain open to examination by the tax jurisdictions to which we are subject.