Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	On December 22, 2017, comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the Tax Act) was enacted by the U.S. government. The Tax Act is generally effective January 1, 2018, and among other changes, reduced the federal corporate income tax rate from 35% to 21%, eliminated the corporate Alternative Minimum Tax, modified numerous insurance-specific provisions, and further limited deductions for executive compensation. The Tax Act reduced the Company’s effective tax rate by 8.8% for the nine month period ended September 30, 2018. There have been no changes to the provisional items that were reflected in the Company’s December 31, 2017 Consolidated Financial Statements associated with the tax effects of the Tax Act related to partnership investments and discounted loss reserves. No material adjustments related to the provisional items for partnership investments are required and the Company is waiting on guidance from the U.S. Treasury regarding the tax impact on discounted loss reserves. Accounting for the tax effects associated with the Tax Act will be completed in the fourth quarter 2018.