Income Taxes

9 Months Ended

Sep. 30, 2021

Income Tax Disclosure [Abstract]

Income Taxes

8. Income Taxes

The effective income tax rate reflects the effect of federal and state income taxes on earnings and the impact of differences in book and tax accounting arising primarily from the permanent tax benefits associated with the statutory depletion deduction for mineral reserves.  For the nine months ended September 30, 2021, the effective income tax rate was 20.6%, which included a $2.9 million discrete benefit for research and development tax credits. For the nine months ended September 30, 2020, the effective income tax rate of 21.0% reflected a $6.9 million discrete benefit from financing third-party railroad track maintenance. In exchange, the Company received a federal income tax credit and deduction.  

The Company records interest accrued in relation to unrecognized tax benefits as income tax expense. Penalties, if incurred, are recorded as operating expenses in the consolidated statements of earnings and comprehensive earnings.