Income Taxes	6 Months Ended
Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	6. Income Taxes The Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) was signed into law on March 27, 2020. Among other provisions, the CARES Act delayed certain employer payroll tax remittance deadlines and created or expanded certain income tax credits and loss carryback provisions and, as a result, Alleghany initially recorded a $6.9 million tax benefit that was subsequently reversed as of June 30, 2020 due to a change in Alleghany’s taxable earnings. The effective tax rate on earnings before income taxes for the first six months of 2020 was 21.7 percent compared with 19.3 percent for the first six months of 2019. The effective tax rate in the first six months of 2020 was calculated based on actual results through June 30, 2020 because management was not able to reliably estimate the annual effective tax rate in light of the significant losses incurred. The increase in the effective tax rate in the first six months of 2020 from the first six months of 2019 primarily reflects higher foreign and state taxes and lower tax-exempt interest income and dividends-received deductions. Alleghany believes that, as of June 30, 2020, 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, 2020.

Income Taxes

6 Months Ended

Jun. 30, 2020

6. Income Taxes

The Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) was signed into law on March 27, 2020. Among other provisions, the CARES Act delayed certain employer payroll tax remittance deadlines and created or expanded certain income tax credits and loss carryback provisions and, as a result, Alleghany initially recorded a $6.9 million tax benefit that was subsequently reversed as of June 30, 2020 due to a change in Alleghany’s taxable earnings.

The effective tax rate on earnings before income taxes for the first six months of 2020 was 21.7 percent compared with 19.3 percent for the first six months of 2019. The effective tax rate in the first six months of 2020 was calculated based on actual results through June 30, 2020 because management was not able to reliably estimate the annual effective tax rate in light of the significant losses incurred. The increase in the effective tax rate in the first six months of 2020 from the first six months of 2019 primarily reflects higher foreign and state taxes and lower tax-exempt interest income and dividends-received deductions.

Alleghany believes that, as of June 30, 2020, 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, 2020.