Income Taxes	6 Months Ended
Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes During the three months ended June 30, 2018 and 2017, the Company recorded approximately $15.2 million and $18.5 million of income tax expense, respectively. The effective tax rate (“ETR”) for the three months ended June 30, 2018 was 24.8% compared to a 38.7% ETR for the same period in 2017. During the six months ended June 30, 2018 and 2017, the Company recorded approximately $26.8 million and $34.7 million of income tax expense, respectively. The ETR for the six months ended June 30, 2018 was 23.7% compared to a 36.4% ETR for the same period in 2017. In arriving at these rates, the Company considers a variety of factors including the forecasted full year pre-tax results, the U.S. federal tax rate, expected non-deductible expenses, and estimated state income taxes. The Company’s final ETR for the full year will be dependent on the level of pre-tax income, discrete items, the apportionment of taxable income among state tax jurisdictions and the extent of non-deductible expenses in relation to pre-tax income. Income tax expense for the three months ended June 30, 2018 included a net credit for discrete items of $0.6 million primarily driven by the excess tax benefits resulting from stock-based compensation awards that were exercised during the second quarter of 2018, benefitting the current quarter’s ETR. For the second quarter of 2017, there were no discrete items. Income tax expense for the six months ended June 30, 2018 included a net credit of $2.3 million primarily driven by the excess tax benefits resulting from stock-based compensation awards that had vested and/or were exercised during that period. The prior year’s discrete items for the six months ended June 30, 2017 were $0.8 million for excess tax benefits resulting from stock-based compensation awards that had vested and/or were exercised during that period, and a credit to income tax expense of $1.2 million resulting from anticipated recoveries of income taxes paid for the 2014-2015 tax years. The Company's income tax provision for the current reporting period reflects an estimated annual ETR of 25.7%, calculated before the impact of discrete items. The statutory tax rate consists of a federal income tax rate of 21% and a state income tax rate, net of federal benefit, of 3.7%. The difference in the statutory tax rate, 24.7%, and the annual ETR, 25.7%, is largely attributable to the new tax law’s impact on Internal Revenue Code Section 162(m). The effect of reporting discrete items in the three months and six months ended June 30, 2018 amounts to an additional decrease to the annual ETR rate of 1.0% and 2.0%, respectively, resulting in a total estimated ETR of 24.8% and 23.7%, respectively. The Company files its tax returns as prescribed by the tax laws of the jurisdictions in which it operates. The Company’s 2014 through 2016 tax years are still subject to examination by the Internal Revenue Service and various tax years remain open to examination in certain state jurisdictions. In February 2018, the Company received notification from the Internal Revenue Service with respect to an examination of the 2015 tax return. The Company is anticipating no adjustments from the examination which is expected to conclude in the third quarter of 2018.

9. Income Taxes

During the three months ended June 30, 2018 and 2017, the Company recorded approximately $15.2 million and $18.5 million of income tax expense, respectively. The effective tax rate (“ETR”) for the three months ended June 30, 2018 was 24.8% compared to a 38.7% ETR for the same period in 2017.

During the six months ended June 30, 2018 and 2017, the Company recorded approximately $26.8 million and $34.7 million of income tax expense, respectively. The ETR for the six months ended June 30, 2018 was 23.7% compared to a 36.4% ETR for the same period in 2017.

In arriving at these rates, the Company considers a variety of factors including the forecasted full year pre-tax results, the U.S. federal tax rate, expected non-deductible expenses, and estimated state income taxes. The Company’s final ETR for the full year will be dependent on the level of pre-tax income, discrete items, the apportionment of taxable income among state tax jurisdictions and the extent of non-deductible expenses in relation to pre-tax income.

Income tax expense for the three months ended June 30, 2018 included a net credit for discrete items of $0.6 million primarily driven by the excess tax benefits resulting from stock-based compensation awards that were exercised during the second quarter of 2018, benefitting the current quarter’s ETR. For the second quarter of 2017, there were no discrete items.

Income tax expense for the six months ended June 30, 2018 included a net credit of $2.3 million primarily driven by the excess tax benefits resulting from stock-based compensation awards that had vested and/or were exercised during that period. The prior year’s discrete items for the six months ended June 30, 2017 were $0.8 million for excess tax benefits resulting from stock-based compensation awards that had vested and/or were exercised during that period, and a credit to income tax expense of $1.2 million resulting from anticipated recoveries of income taxes paid for the 2014-2015 tax years.

The Company's income tax provision for the current reporting period reflects an estimated annual ETR of 25.7%, calculated before the impact of discrete items. The statutory tax rate consists of a federal income tax rate of 21% and a state income tax rate, net of federal benefit, of 3.7%. The difference in the statutory tax rate, 24.7%, and the annual ETR, 25.7%, is largely attributable to the new tax law’s impact on Internal Revenue Code Section 162(m). The effect of reporting discrete items in the three months and six months ended June 30, 2018 amounts to an additional decrease to the annual ETR rate of 1.0% and 2.0%, respectively, resulting in a total estimated ETR of 24.8% and 23.7%, respectively.

The Company files its tax returns as prescribed by the tax laws of the jurisdictions in which it operates. The Company’s 2014 through 2016 tax years are still subject to examination by the Internal Revenue Service and various tax years remain open to examination in certain state jurisdictions. In February 2018, the Company received notification from the Internal Revenue Service with respect to an examination of the 2015 tax return. The Company is anticipating no adjustments from the examination which is expected to conclude in the third quarter of 2018.