Income Taxes	9 Months Ended
Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes The effective income tax rate was 38.7% for the three months ended September 30, 2015 and 32.8% for the three months ended September 30, 2014. The effective tax rate during the third quarter of 2014 was impacted by net contingent earnout adjustments of $3.3 million related to prior acquisitions in the TL segment. The effective income tax rate was 38.7% for the nine months ended September 30, 2015 and 36.7% for the nine months ended September 30, 2014. The effective tax rate during the first nine months of 2014 was impacted by net contingent earnout adjustments of $3.9 million related to prior acquisitions in the TL segment. In determining the provision for income taxes, the Company used an estimated annual effective tax rate, which was based on expected annual income, statutory tax rates, and the Company's best estimate of non-deductible and non-taxable items of income and expense. Income tax expense varies from the amount computed by applying the federal corporate income tax rate of 35.0% to income before income taxes primarily due to state income taxes, net of federal income tax effect, and adjustments for permanent differences.

Income Taxes

9 Months Ended

Sep. 30, 2015

8. Income Taxes

The effective income tax rate was 38.7% for the three months ended September 30, 2015 and 32.8% for the three months ended September 30, 2014. The effective tax rate during the third quarter of 2014 was impacted by net contingent earnout adjustments of $3.3 million related to prior acquisitions in the TL segment. The effective income tax rate was 38.7% for the nine months ended September 30, 2015 and 36.7% for the nine months ended September 30, 2014. The effective tax rate during the first nine months of 2014 was impacted by net contingent earnout adjustments of $3.9 million related to prior acquisitions in the TL segment. In determining the provision for income taxes, the Company used an estimated annual effective tax rate, which was based on expected annual income, statutory tax rates, and the Company's best estimate of non-deductible and non-taxable items of income and expense. Income tax expense varies from the amount computed by applying the federal corporate income tax rate of 35.0% to income before income taxes primarily due to state income taxes, net of federal income tax effect, and adjustments for permanent differences.