Income Taxes	3 Months Ended
Mar. 31, 2012
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective income tax rate for the three months ended March 31, 2012 and 2011 was 37.8% and 40.1%, respectively. The Company's provision for income taxes differed from the U.S. statutory rate of 35% primarily due to state income taxes, domestic production activities deduction, percentage depletion, nondeductible employee compensation and other permanent differences. Additionally, the effective income tax rate in the three months ended March 31, 2011 differs from the statutory rate due to a one-time reduction in deferred state income taxes as a result of acquisitions in more favorable jurisdictions, reducing future state income tax obligations. This benefit increased the effective income tax rate due to the Company's reporting a loss in the first quarter of 2011. As of March 31, 2012, the Company had a gross liability for uncertain income tax benefits of $2.9 million, which, if recognized, would affect the effective income tax rate. There have been no significant changes to the calculation of uncertain income tax benefits during 2012. Consistent with the Company's policy, interest and penalties on income taxes have been recorded as a component of the income tax provision (benefit). The Company estimates that it is reasonably possible that the balance of unrecognized income tax benefits as of March 31, 2012 could decrease by a maximum of $2.7 million in the next 12 months due to the expiration of statutes of limitation and audit settlements.

Income Taxes

3 Months Ended

Mar. 31, 2012

The effective income tax rate for the three months ended March 31, 2012 and 2011 was 37.8% and 40.1%, respectively. The Company's provision for income taxes differed from the U.S. statutory rate of 35% primarily due to state income taxes, domestic production activities deduction, percentage depletion, nondeductible employee compensation and other permanent differences. Additionally, the effective income tax rate in the three months ended March 31, 2011 differs from the statutory rate due to a one-time reduction in deferred state income taxes as a result of acquisitions in more favorable jurisdictions, reducing future state income tax obligations. This benefit increased the effective income tax rate due to the Company's reporting a loss in the first quarter of 2011.

As of March 31, 2012, the Company had a gross liability for uncertain income tax benefits of $2.9 million, which, if recognized, would affect the effective income tax rate. There have been no significant changes to the calculation of uncertain income tax benefits during 2012. Consistent with the Company's policy, interest and penalties on income taxes have been recorded as a component of the income tax provision (benefit). The Company estimates that it is reasonably possible that the balance of unrecognized income tax benefits as of March 31, 2012 could decrease by a maximum of $2.7 million in the next 12 months due to the expiration of statutes of limitation and audit settlements.