Income Taxes	6 Months Ended
Jun. 30, 2018
Income Taxes	6. Income Taxes The effective tax rate on earnings before income taxes for the first six months of 2018 was 19.1 percent, compared with 27.6 percent for the first six months of 2017. The decrease in the effective tax rate in the first six months of 2018 from the first six months of 2017 primarily reflects the decrease in the U.S. corporate federal income tax rate from 35.0 percent to 21.0 percent due to the Tax Act, partially offset by new limitations on certain deductions as a result of the Tax Act. There continues to be a degree of uncertainty as to how certain provisions of the Tax Act will be interpreted and implemented in practice in the future. Alleghany believes that, as of June 30, 2018, it had no material uncertain tax positions. Interest and penalties related to unrecognized tax expenses (benefits) are recognized in income tax expense, when applicable. There were no material liabilities for interest or penalties accrued as of June 30, 2018.

6. Income Taxes

The effective tax rate on earnings before income taxes for the first six months of 2018 was 19.1 percent, compared with 27.6 percent for the first six months of 2017. The decrease in the effective tax rate in the first six months of 2018 from the first six months of 2017 primarily reflects the decrease in the U.S. corporate federal income tax rate from 35.0 percent to 21.0 percent due to the Tax Act, partially offset by new limitations on certain deductions as a result of the Tax Act. There continues to be a degree of uncertainty as to how certain provisions of the Tax Act will be interpreted and implemented in practice in the future.

Alleghany believes that, as of June 30, 2018, it had no material uncertain tax positions. Interest and penalties related to unrecognized tax expenses (benefits) are recognized in income tax expense, when applicable. There were no material liabilities for interest or penalties accrued as of June 30, 2018.