Income Taxes	3 Months Ended
Mar. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes At the end of each interim period, we estimate our annual effective tax rate and apply that rate to our interim earnings. We also record the tax impact of certain unusual or infrequently occurring items, including changes in judgment about valuation allowances and the effects of changes in tax laws or rates, in the interim period in which they occur. The computation of the annual estimated effective tax rate at each interim period requires certain estimates and significant judgment including, but not limited to, the expected operating income for the year, projections of the proportion of income earned and taxed in state and foreign jurisdictions, permanent and temporary differences between book and taxable income, and the likelihood of recovering deferred tax assets generated in the current year. The accounting estimates used to compute the provision for income taxes may change as new events occur, additional information is obtained or as the tax environment changes. Our effective income tax rate for the three months ended March 31, 2014 was 34.0% compared with 35.8% for the comparable prior year period. The lower effective income tax rate for the three months ended March 31, 2014 is primarily as a result of our expanding international operations as a larger proportion of our pretax income was generated in lower tax rate jurisdictions, combined with lower statutory tax rates in effect in the U.K. compared to the prior year.

Income Taxes

3 Months Ended

Mar. 31, 2014

At the end of each interim period, we estimate our annual effective tax rate and apply that rate to our interim earnings. We also record the tax impact of certain unusual or infrequently occurring items, including changes in judgment about valuation allowances and the effects of changes in tax laws or rates, in the interim period in which they occur.

The computation of the annual estimated effective tax rate at each interim period requires certain estimates and significant judgment including, but not limited to, the expected operating income for the year, projections of the proportion of income earned and taxed in state and foreign jurisdictions, permanent and temporary differences between book and taxable income, and the likelihood of recovering deferred tax assets generated in the current year. The accounting estimates used to compute the provision for income taxes may change as new events occur, additional information is obtained or as the tax environment changes.

Our effective income tax rate for the three months ended March 31, 2014 was 34.0% compared with 35.8% for the comparable prior year period. The lower effective income tax rate for the three months ended March 31, 2014 is primarily as a result of our expanding international operations as a larger proportion of our pretax income was generated in lower tax rate jurisdictions, combined with lower statutory tax rates in effect in the U.K. compared to the prior year.