Document and Entity Information [Abstract] No definition available. Entity Registrant Name Entity Central Index Key Document Type Document Period End Date Amendment Flag Document Fiscal Year Focus Document Fiscal Period Focus Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Public Float Entity Common Stock, Shares Outstanding (actual number of shares) Reinsurance Recoverables Reinsurance Recoverable on Unpaid Losses and Loss Expenses Reinsurance recoverable, beginning of year Reinsurance Recoverable on Unpaid Losses and Loss Expenses Segment Reporting Information, by Segment [Axis] Reporting Segment [Domain] Net Income (Loss) Attributable to Parent Net Income Net Income GAAP net income (loss) Earnings Per Share, Basic Basic earnings per share Basic Earnings Per Share, Diluted Diluted earnings per share Diluted Deferred Tax Assets (Liabilities), Net Net deferred income tax asset Deferred Tax Assets (Liabilities), Net, Total Deferred Income Tax Other Invested Assets This item represents other invested assets which include investments such as private equity limited partnerships carried at the Corporation's equity in the net assets of the partnerships and warrants reported at fair value. Other invested assets Other Invested Assets Other invested assets Income Tax Expense (Benefit) Federal and Foreign Income Tax (Credit) Federal and Foreign Income Tax Actual tax Depreciation Premises and Equipment Depreciation Depreciation expense related to property and equipment Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Cumulative Effects of Changes in Accounting Principles, Noncontrolling Interest Loss before Federal and Foreign Income Tax and Equity in Net Income of Consolidated Subsidiaries Income before federal and foreign income tax Total income before income tax Income before federal and foreign income tax Income Before Federal and Foreign Income Tax Stockholders' Equity Attributable to Parent Balance, End of Year Balance, End of Year TOTAL SHAREHOLDERS' EQUITY Shareholders' equity Revenues Total Revenues Total Revenues Revenues Total Losses And Expenses Total Losses and Expenses Losses and expenses The total amount of losses and expenses recognized during the period. Deferred Policy Acquisition Cost, Amortization Expense Amortization of Deferred Policy Acquisition Costs Amortization during year Amortization during year Amortization of Deferred Policy Acquisition Costs Long-term Debt Long term debt Long-term Debt, Total Long Term Debt Corporate bonds [Member] Investment Type [Axis] Investment Type [Domain] Deferred Policy Acquisition Costs Balance, end of year Balance, beginning of year Deferred Policy Acquisition Costs, Total Deferred Policy Acquisition Costs Foreign government and government agency obligations [Member] CONSOLIDATED BALANCE SHEETS [Abstract] CONDENSED FINANCIAL INFORMATION OF REGISTRANT BALANCE SHEETS - PARENT COMPANY ONLY CONSOLIDATED STATEMENTS OF INCOME [Abstract] CONDENSED FINANCIAL INFORMATION OF REGISTRANT STATEMENTS OF INCOME - PARENT COMPANY ONLY CONSOLIDATED STATEMENT OF CASH FLOWS [Abstract] CONDENSED FINANCIAL INFORMATION OF REGISTRANT STATEMENTS OF CASH FLOWS - PARENT COMPANY ONLY Liabilities and Stockholders' Equity TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY Assets [Abstract] Assets Liabilities [Abstract] Liabilities [Abstract] Liabilities Stockholders' Equity Attributable to Parent [Abstract] Shareholders' Equity [Abstract] Shareholders' Equity Treasury Stock, Value Treasury Stock, at Cost - 79,435,213 and 74,707,547 Shares Treasury Stock, Value, Ending Balance Treasury Stock, Value, Beginning Balance Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance Accumulated Other Comprehensive Income (Loss), Net of Tax, Total Accumulated Other Comprehensive Income Retained Earnings (Accumulated Deficit) Retained Earnings (Accumulated Deficit), Ending Balance Retained Earnings (Accumulated Deficit), Beginning Balance Retained Earnings (Accumulated Deficit), Total Retained Earnings Additional Paid in Capital Additional Paid in Capital, Ending Balance Additional Paid in Capital, Beginning Balance Additional Paid in Capital, Total Paid-In Surplus Common Stock, Value, Issued Common Stock, Value, Issued, Ending Balance Common Stock, Value, Issued, Beginning Balance Common Stock, Value, Issued, Total Common Stock - $1 Par Value; 371,980,460 Shares Liabilities TOTAL LIABILITIES Other Liabilities Accrued Expenses and Other Liabilities Dividends Payable Dividend Payable to Shareholders Assets TOTAL ASSETS Total assets Other Assets Other Assets TOTAL INVESTED ASSETS Investments TOTAL INVESTED ASSETS Equity Securities (cost $1,305 and $1,285) Available-for-sale Securities, Equity Securities Equity securities, Fair value Equity securities, Fair value Revenues [Abstract] Revenues Other Nonoperating Expense Other Nonoperating Expense, Total Other Expenses Investment Income, Investment Expense Investment expenses Investment Expenses Corporate Expenses The total amount of expenses incurred by the entity related to corporate activities, including interest expense. Corporate Expenses Gain (Loss) on Investments Realized Investment Gains, Net Total Realized Losses, Net Realized investment gains, Net Total Realized Investment Gains, Net Total realized investment gains and losses Other Income Other Revenues Interest and Dividend Income, Operating Investment income Investment Income Investment Income Equity Securities, Cost This item represents the cost basis of equity securities. Equity Securities, Cost Common Stock, Par or Stated Value Per Share Common Stock, Par Value Common Stock, Shares, Issued Common Stock, Shares, Issued, Total Common Stock, Shares Issued Net Cash Provided by (Used in) Operating Activities [Abstract] Cash Flows from Operating Activities [Abstract] Cash Flows from Operating Activities Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash Flows from Investing Activities [Abstract] Cash Flows from Investing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash Flows from Financing Activities [Abstract] Cash Flows from Financing Activities Cash Period Increase Decrease Net Increase in Cash Net Decrease in Cash The net change between the beginning and ending balance of unrestricted cash available for day-to-day operating needs. Net Cash Provided by (Used in) Financing Activities Net Cash Used in Financing Activities Payments of Dividends, Common Stock Dividends Paid to Shareholders Dividends Paid to Shareholders Dividends Paid to Shareholders Payments for Repurchase of Common Stock Repurchase of Shares Proceeds from Stock Plans Proceeds from Issuance of Common Stock Under Stock-Based Employee Compensation Plans Net Cash Provided by (Used in) Investing Activities Net Cash Used in Investing Activities NET CASH PROVIDED BY INVESTING ACTIVITIES Payments for (Proceeds from) Short-term Investments Increase in Short Term Investments, Net Payments for (Proceeds from) Short-term Investments, Total Payments to Acquire Available-for-sale Securities, Debt Purchases of Fixed Maturities Proceeds from Sale of Available-for-sale Securities, Equity Proceeds from Sales of Equity Securities Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities Proceeds from Fixed Maturities - Maturities, Calls and Redemptions Proceeds from Sale of Available-for-sale Securities, Debt Proceeds from Fixed Maturities - Sales Net Cash Provided by (Used in) Operating Activities Net Cash Provided by Operating Activities NET CASH USED IN OPERATING ACTIVITIES Increase (Decrease) in Other Operating Assets and Liabilities, Net Other, Net Other, Net Other, Net Other Comprehensive Income Loss Net Of Tax Period Increase Decrease Total Other Comprehensive Income (Loss), Net of Tax Total Other Comprehensive Income, Net of Tax Total Other Comprehensive Income, Net of Tax Supplementary Insurance Information, Segment Name [Axis] Supplementary Insurance Information, Segment Name [Domain] Premiums Earned Premiums Earned, Net, Property and Casualty Net premiums earned Other Short-term Investments Short term investments Short Term Investments Other Comprehensive Income, Defined Benefit Plans Adjustment, Net of Tax Foreign Currency Translation Gains (Losses) Amortization of Net Actuarial Loss and Prior Service Cost Included in Net Postretirement Benefit Costs Change in postretirement benefit costs not yet recognized in net income, Net of tax Liability for Claims and Claims Adjustment Expense, Property Casualty Liability Gross liability, end of year Gross liability, beginning of year Unpaid Losses and Loss Expenses Unpaid losses, Personal Incurred Claims, Property, Casualty and Liability Insurance Losses Net incurred losses and loss expenses, total Losses and Loss Expenses Unearned Premiums Unearned Premiums, Total Unearned Premiums Other Underwriting Expense Other Insurance Operating Costs and Expenses Amortized Cost And Fair Value Of Fixed Maturities And Equity Securities [Text Block] Amortized cost and fair value of fixed maturities and equity securities Amortized cost and fair value of fixed maturities and equity securities by investment category. Amortized Cost And Fair Value Of Fixed Maturities By Contractual Maturity [Text Block] Amortized cost and fair value of fixed maturities by contractual maturity Amortized cost and fair value of fixed maturities by contractual maturity. Components Of Unrealized Appreciation Or Depreciation Of Investments [Text Block] Components of unrealized appreciation or depreciation of investments Components of unrealized appreciation and depreciation, including unrealized other-than-temporary impairment losses, of investments carried at fair value. Fair Value And Gross Unrealized Depreciation Of Investments In Unrealized Loss Position [Text Block] Fair value and gross unrealized depreciation of investments in an unrealized loss position The aggregate fair value and gross unrealized depreciation, including other-than-temporary impairment losses, by investment category and length of time that individual securities have continuously been in an unrealized loss position for all investment securities in an unrealized loss position. Change In Unrealized Appreciation Or Depreciation Of Investments Carried At Fair Value [Text Block] Change in unrealized appreciation or depreciation of investments carried at fair value Change in unrealized appreciation or depreciation of investments carried at fair value, including the change in unrealized other-than-temporary impairment losses. Gain (Loss) on Investments [Text Block] Realized investment gains and losses Tax exempt, cost Tax exempt, Amortized cost Tax exempt, Cost This item represents the amortized cost basis of tax exempt debt securities that are categorized as neither held-to-maturity nor trading. Tax exempt, Gross Unrealized Appreciation Tax exempt, Gross unrealized appreciation Tax exempt, Gross Unrealized Appreciation The excess of the fair value of tax exempt fixed maturities over its amortized cost which excess value has not been recognized in earnings of the entity. Tax exempt, Gross Unrealized Depreciation Tax exempt, Gross unrealized depreciation Tax exempt, Gross unrealized depreciation The excess of amortized cost of tax exempt fixed maturities over its fair value which deficiency has not been recognized in earnings of the entity. Tax Exempt Tax Exempt (cost $19,156 and $19,072) Tax exempt, Fair value Tax exempt, Fair value This item represents total tax-exempt debt securities that are categorized as neither held-to-maturity nor trading. Such securities are reported at fair value; unrealized gains and losses of such securities are excluded from earnings and included in other comprehensive income. Taxable, Cost Taxable, Amortized cost Taxable, Cost Taxable, Amortized cost This item represents the amortized cost basis of taxable debt securities that are categorized as neither held-to-maturity nor trading. Taxable, Gross Unrealized Appreciation Taxable, Gross unrealized appreciation Taxable, Gross unrealized appreciation The excess of the fair value of taxable fixed maturities over its amortized cost which excess value has not been recognized in earnings of the entity. Taxable, Gross Unrealized Depreciation Taxable, Gross unrealized depreciation Taxable, Gross unrealized depreciation The excess of amortized cost of taxable fixed maturities over its fair value which deficiency has not been recognized in earnings of the entity. Taxable Taxable (cost $16,037 and $15,989) Taxable, Fair value Taxable, Fair value This item represents total taxable debt securities that are categorized as neither held-to-maturity nor trading. Such securities are reported at fair value; unrealized gains and losses of such securities are excluded from earnings and included in other comprehensive income. Fixed Maturities Cost Total fixed maturities, Amortized cost Total fixed maturities, Amortized cost This item represents the amortized cost basis of investments in debt securities having predetermined or determinable maturity dates. Fixed Maturities Gross Unrealized Appreciation Total fixed maturities, Gross unrealized appreciation Fixed maturities, Gross unrealized appreciation The excess of the fair value of fixed maturities over its amortized cost which excess value has not been recognized in earnings of the entity. Fixed Maturities Gross Unrealized Depreciation Total fixed maturities, Gross unrealized depreciation Fixed maturities, Gross unrealized depreciation The excess of amortized cost of fixed maturities over its fair value which deficiency has not been recognized in earnings of the entity. Fixed Maturities Fixed Maturities (Note-X) Total fixed maturities, Fair value Total fixed maturities This item represents total fixed maturities that are categorized as neither held-to-maturity nor trading. Such securities are reported at fair value; unrealized gains and losses of such securities are excluded from earnings and included in other comprehensive income. Equity securities, Gross Unrealized Appreciation Equity securities, Gross Unrealized Appreciation Equity securities, Gross Unrealized Appreciation Equity securities, Gross unrealized appreciation Equity securities, Gross unrealized appreciation Equity securities, Gross unrealized appreciation The excess of the fair value of equity securities over its amortized cost which excess value has not been recognized in earnings of the entity. Equity securities, Gross Unrealized Depreciation Equity securities, Gross unrealized depreciation Equity securities, Gross Unrealized Depreciation The excess of amortized cost of equity securities over its fair value which deficiency has not been recognized in earnings of the entity. Residential Mortgage-Backed Securities [Member] Commercial Mortgage-Backed Securities [Member] Amortized cost and fair value of fixed maturities by contractual maturity [Abstract] No definition available. Amortized cost and fair value of fixed maturities by contractual maturity [Abstract] Available-for-sale Securities, Debt Maturities, within One Year, Amortized Cost Due in one year or less, Amortized cost Available-for-sale Securities, Debt Maturities, within One Year, Fair Value Due in one year or less, Fair value Available-for-sale Securities, Debt Maturities, after One Through Five Years, Amortized Cost Due after one year through five years, Amortized cost Available-for-sale Securities, Debt Maturities, after One Through Five Years, Fair Value Due after one year through five years, Fair value Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Amortized Cost Due after five years through ten years, Amortized cost Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value Due after five years through ten years, Fair value Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Due after ten years, Amortized cost Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value Due after ten years, Fair value Available-for-sale Securities, Debt Maturities, Amortized Cost Subtotal fixed maturities, Amortized cost Subtotal fixed maturities, Cost Available-for-sale Securities, Debt Maturities, Fair Value Subtotal fixed maturities, Fair value Subtotal fixed maturities, Fair value Components of unrealized appreciation or depreciation of investments [Abstract] No definition available. Components of unrealized appreciation or depreciation of investments [Abstract] Total fixed maturities and equity securities, Unrealized appreciation (depreciation), net of tax Total fixed maturities and equity securities, Unrealized appreciation (depreciation), Net of tax Total fixed maturities and equity securities, Unrealized appreciation (depreciation), net of tax The net excess or deficiency of the fair value of fixed maturities and equity securities over or under its amortized cost which has not been recognized in earnings of the entity net of deferred income tax. Deferred Income Tax Asset Liability Deferred income tax liability Deferred income tax liability Deferred income tax liability The amount for all deferred tax assets and liabilities relating to unrealized appreciation or depreciation as of the balance sheet date. Total fixed maturities and equity securities, Unrealized appreciation (depreciation), net Total fixed maturities and equity securities, Unrealized appreciation (depreciation), Net Total fixed maturities and equity securities, Unrealized appreciation (depreciation), net The net excess or deficiency of the fair value of available for sale securities over or under its amortized cost which has not been recognized in earnings of the entity. Equity securities, Unrealized appreciation (depreciation), net Equity securities, Unrealized appreciation (depreciation), net Equity securities, Unrealized appreciation (depreciation), Net The net excess or deficiency of the fair value of equity securities over or under its amortized cost which has not been recognized in earnings of the entity. Fixed maturities, Unrealized appreciation (depreciation), net Fixed maturities, Unrealized appreciation (depreciation), Net Fixed maturities, Unrealized appreciation (depreciation), net The net excess or deficiency of the fair value of fixed maturities over or under its amortized cost which has not been recognized in earnings of the entity. Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities, Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Schedule of Available-for-sale Securities [Line Items] Fair value and gross unrealized depreciation of investments in an unrealized loss position [Abstract] Fair value and gross unrealized depreciation of investments in an unrealized loss position [Abstract] Fixed Maturities Equity Securities Gross Unrealized Depreciation Total fixed maturities and equity securities, Gross unrealized depreciation Total fixed maturities and equity securities, Gross unrealized depreciation Total fixed maturities and equity securities, Gross unrealized depreciation The excess of amortized cost of fixed maturities and equity securities over its fair value which deficiency has not been recognized in earnings of the entity. Marketable Securities Total fixed maturities and equity securities Total fixed maturities and equity securities Total fixed maturities and equity securities, Fair value Twelve months or more [Member] Individual securities which have been continuously in an unrealized loss position twelve months or more. Less than twelve months [Member] Individual securities which have been continuously in an unrealized loss position less than twelve months. Change in unrealized appreciation or depreciation of investments carried at fair value [Abstract] No definition available. Change in unrealized appreciation or depreciation of investments carried at fair value Fixed Maturities Change In Unrealized Appreciation Or Depreciation Change in unrealized appreciation or depreciation of fixed maturities Change in unrealized appreciation of fixed maturities This item represents the change in net unrealized holding gain or loss on fixed maturities that has been included in accumulated other comprehensive income, a separate component of shareholders' equity, during the period. Equity Securities Change In Unrealized Appreciation Or Depreciation Change in unrealized appreciation or depreciation of equity securities Change in unrealized appreciation of equity securities This item represents the change in net unrealized holding gain or loss on equity securities that has been included in accumulated other comprehensive income, a separate component of shareholders' equity, during the period. Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss) Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Total Change in unrealized appreciation of fixed maturities and equity securities Available-for-sale Securities, Income Tax Expense on Change in Unrealized Holding Gain or Loss Deferred income tax (credit) Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Net of Tax Total change in unrealized appreciation of fixed maturities and equity securities, Net of tax Realized investment gains and losses [Abstract] No definition available. Realized investment gains and losses Gross Realized Gains Fixed Maturities Fixed maturities, Gross realized gains This item represents the gross profit realized on the sale of fixed maturities categorized neither as held-to-maturity nor trading securities. Gross Realized Losses Fixed Maturities Fixed maturities, Gross realized losses This item represents the gross loss realized on the sale of fixed maturities categorized neither as held-to-maturity nor trading securities. Impairment Of Investments Fixed Maturities Fixed maturities, Other-than-temporary impairment losses Fixed maturities, Other-than-temporary impairment losses The amount charged to income if the decline in fair value for fixed maturities is deemed to be other than temporary. Gross Realized Gains Equity Securities Equity securities, Gross realized gains This item represents the gross profit realized on the sale of equity securities categorized neither as held-to-maturity nor trading securities. Impairment Of Investments Equity Securities Equity securities, Other-than-temporary impairment losses Impairment Of Investments Equity Securities The amount charged to income if the decline in fair value for equity securities is deemed to be other than temporary. Other Invested Assets Gain Loss Other invested assets Other invested assets This item represents the gross realized gain (loss) included in earnings for the period as a result of selling or holding other invested assets. Net Investment Income, Insurance Entity Net investment income Net investment income Investment income Invested Assets (Textuals) [Abstract] No definition available. Invested Assets (Textuals) [Abstract] Fixed Maturities Other Than Temporary Impairment Losses In Gross Unrealized Depreciation Fixed maturities other-than-temporary impairment losses in gross unrealized depreciation Fixed maturities other-than-temporary impairment losses in gross unrealized depreciation. Individual Fixed Maturity And Equity Securities In Unrealized Loss Position Individual fixed maturity and equity securities in unrealized loss position Individual fixed maturity security and equity securities which were in an unrealized loss position. Individual Fixed Maturities In Unrealized Loss Position Individual fixed maturities in unrealized loss position Individual fixed maturities which were in an unrealized loss position. Cumulative credit losses recognized in net income Cumulative credit-related losses, recognized in net income, related to fixed maturities held, for which a portion of their other-than-temporary impairment losses were recognized in other comprehensive income. Cumulative credit losses recognized in net income Accounting Pronouncements Not Yet Adopted [Text Block] Accounting Pronouncements Not Yet Adoption Accounting Pronouncements Not Yet Adopted Description of accounting pronouncements not yet adopted. Earnings Per Share [Text Block] Earnings Per Share Earnings Per Share (Tables) [Abstract] No definition available. Computation Of Basic And Diluted Earnings Per Share [Text Block] Computation of basic and diluted earnings per share A table disclosing the computation of basic and diluted earnings per share. Earnings Per Share (Details) [Abstract] No definition available. Weighted Average Number of Shares Outstanding, Basic Weighted average shares outstanding Weighted average shares outstanding Incremental Common Shares Attributable to Share-based Payment Arrangements Additional shares from assumed exercise of stock-based compensation awards Additional shares from assumed exercise of stock-based compensation awards Weighted Average Number of Shares Outstanding, Diluted Weighted average shares and potential shares assumed outstanding for computing diluted earnings per share Weighted average shares and potential shares assumed outstanding for computing diluted earnings per share Earnings Per Share, Basic [Abstract] Basic earnings per share [Abstract] Earnings Per Share, Diluted [Abstract] Diluted earnings per share [Abstract] Earnings Per Share [Abstract] Net Income Per Share Segments Information [Abstract] No definition available. Segment Reporting Disclosure [Text Block] Segments Information Segments Information (Tables) [Abstract] No definition available. Segments Information (Details) [Abstract] No definition available. Property and casualty insurance [Member] This element represents property and casualty insurance businesses. Specialty insurance [Member] Specialty insurance [Member] The specialty segment includes those classes of business that are available in more limited markets since they require specialized underwriting and claim settlement. Specialty classes include professional liability coverages and surety. Total insurance [Member] All property and casualty insurance business, excluding reinsurance assumed that is in run-off. Total insurance [Member] Premiums Earned From Insurance Premiums earned related to insurance business Premiums recognized as revenue in the period earned on all property and casualty insurance and reinsurance contracts after subtracting any amounts ceded to another insurer and before reinsurance assumed business which is in run-off. Premiums Earned From Reinsurance Assumed Premiums earned related to reinsurance assumed Premiums earned related to reinsurance assumed Premiums recognized as revenue in the period earned on property and casualty reinsurance assumed business which is in run-off, after subtracting any amounts ceded to another insurer. Total property and casualty insurance revenues Total revenues recognized in the period for property and casualty insurance including premiums earned and investment income before realized investment gains or losses. Total Property And Casualty Insurance Revenues Total property and casualty insurance revenues Corporate and other revenues Corporate and other revenues Represents revenues related to non-insurance companies, before realized investment gains or losses. Insurance Underwriting Income Underwriting income related to insurance business Amount of underwriting income (loss) for the reportable segments which is arrived at by reducing premiums earned by losses and loss expenses incurred and statutory underwriting expenses incurred, before reinsurance assumed business which is in run-off. Under statutory accounting principles, policy acquisition and other underwriting expenses are recognized immediately, not at the time premiums are earned. Reinsurance assumed underwriting income Reinsurance assumed underwriting income Reinsurance assumed underwriting income Amount of underwriting income (loss) for reinsurance assumed segment, which is in run-off, which is arrived at by reducing premiums earned by losses and loss expenses incurred and statutory underwriting expenses incurred. Under statutory accounting principles, policy acquisition and other underwriting expenses are recognized immediately, not at the time premiums are earned. Statutory underwriting income Amount of underwriting income (loss) for the property and casualty insurance segments which is arrived at by reducing premiums earned by losses and loss expenses incurred and statutory underwriting expenses incurred. Under statutory accounting principles, policy acquisition and other underwriting expenses are recognized immediately, not at the time premiums are earned. Statutory underwriting income Increase (decrease) in deferred policy acquisition cost Increase in deferred policy acquisition cost Increase in deferred policy acquisition cost The net change during the reporting period in the balance sheet value, excluding foreign currency translation effect, of capitalized sales costs that are associated with acquiring a new insurance customers. Total Underwriting Income Underwriting income Amount of underwriting income (loss) for the property and casualty insurance segments which is arrived at by reducing premiums earned by losses and loss expenses incurred and generally accepted accounting principles (GAAP) underwriting expenses incurred. Under GAAP, policy acquisition expenses are deferred and amortized over the period in which the related premiums are earned. Other income (charges) Other income (charges) Other income (charges) Reflects the sum of all other income and charges recognized by the entity in the period not otherwise specified separately. Property And Casualty Insurance Income Before Taxes And Corporate Companies Total property and casualty insurance Amount of income (loss) before income tax for property and casualty insurance including underwriting income (loss), investment income (loss) and other income (charges), before realized investment gain (loss). Corporate And Other Income Loss Corporate and other loss Represents income (loss) before income tax related to non-insurance companies before realized investment gain (loss). Schedule of Segment Reporting Information, by Segment [Table] Segment Reporting Information [Line Items] Level 1 [Member] Level 2 [Member] Level 3 [Member] Fair Value, by Balance Sheet Grouping [Text Block] Carrying values and fair values of financial instruments Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Fair Value, Disclosure Item Amounts [Domain] Carrying Value [Member] Fair Value [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Assets Measured on Recurring Basis [Table] Fair Value, Assets Measured on Recurring Basis, Disclosure Items [Axis] Fair Value, Assets Measured on Recurring Basis, Disclosure Items [Domain] Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] Fair Values of Financial Instruments (Tables) [Abstract] No definition available. Fair Values of Financial Instruments (Details) [Abstract] No definition available. Carrying values and fair values of financial instruments [Abstract] No definition available. Carrying values and fair values of financial instruments [Abstract] Fair Values of Financial Instruments (Textual) [Abstract] No definition available. Fair Values of Financial Instruments (Textual) [Abstract] Percentage of fair value amounts for fixed maturities provided by pricing service Percentage of fair value amounts for fixed maturities provided by a pricing service Percentage of fair value amounts for fixed maturities provided by a pricing service. TOTAL INVESTED ASSETS Cash Cash at End of Period Cash at Beginning of Year Cash Assets TOTAL ASSETS TOTAL ASSETS Other Assets Other Assets Other Assets Goodwill Premiums Receivable Reinsurance Recoverable on Unpaid Losses and Loss Expenses Prepaid Reinsurance Premiums Deferred Policy Acquisition Costs Accrued Investment Income Unearned Premiums Liabilities and Stockholders' Equity TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY Stockholders' Equity Attributable to Parent TOTAL SHAREHOLDERS' EQUITY TOTAL SHAREHOLDERS' EQUITY Liabilities TOTAL LIABILITIES TOTAL LIABILITIES Long Term Debt Accrued Expenses and Other Liabilities Common Stock - $1 Par Value; 371,980,460 Shares Common Stock - $1 Par Value; 371,980,710 and 374,649,923 Shares Common Stock, Value, Ending Balance Common Stock, Value, Beginning Balance Common Stock, Value, Total Common Stock, Par Value Treasury Stock, Shares Treasury Stock, at Cost - 16,279,184 Shares in 2008 Treasury Stock, at Cost - 67,047,923 and 39,972,796 Shares Treasury Stock, at Cost - 67,047,923 and 39,972,796 Shares Treasury Stock, Value, Ending Balance Treasury Stock, Value, Beginning Balance Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income (Loss) Retained Earnings Common Stock, Shares, Outstanding Interest And Dividend Income Operating Investment income Interest and Dividend Income, Operating, Total Investment Income Other Income Other Revenues Revenues Total Revenues Total Revenues Gain (Loss) on Investments Realized Investment Losses (Gains), Net Total Realized Gains (Losses), Net Total invested assets Total Realized Gains (Losses), Net Realized investment gains (losses), net Amortization of Deferred Policy Acquisition Costs Income (Loss) from Continuing Operations before Income Taxes, Minority Interest, and Income (Loss) from Equity Method Investments Total income before income tax Income Before Federal and Foreign Income Tax Net Income Earnings Per Share, Basic Basic earnings per share Basic Earnings Per Share, Diluted Diluted earnings per share Diluted Investment Expenses Comprehensive Income, Net of Tax, Attributable to Parent Comprehensive Income Net Income Net Cash Provided by (Used in) Operating Activities Net Cash Provided by Operating Activities Net Cash Provided by Operating Activities Net Cash Provided by Operating Activities Increase decrease in other operating capital net Other, Net Other, Net Other, Net Depreciation Amortization of Premiums and Discounts on Fixed Maturities Amortization of Premiums and Discounts on Fixed Maturities Amortization of Premiums and Discounts on Fixed Maturities Decrease in Unearned Premiums, Net Decrease in Unearned Premiums, Net Increase (Decrease) in Unearned Premiums, Net Decrease in Premiums Receivable Decrease in Premiums Receivable Increase in Premiums Receivable Net Cash Provided by (Used in) Investing Activities Net Cash Used in Investing Activities Net Cash Used in Investing Activities Net Cash Used in Investing Activities Net Cash Provided by (Used in) Investing Activities Payments for proceeds from other investing activities Other, Net Other, Net Other, Net Other, Net Net Cash Provided by (Used in) Financing Activities Net Cash Used in Financing Activities Net Cash Used in Financing Activities Net Cash Used in Financing Activities Purchases of Equity Securities Other Expenses Other Comprehensive Income (Loss), Net of Tax, Period Increase (Decrease) Change During Year, Net of Tax Total Other Comprehensive Income, Net of Tax Total Other Comprehensive Income (Loss), Net of Tax Dividends Paid to Shareholders Dividends Paid to Shareholders Dividends Paid to Shareholders Dividends Paid to Shareholders Repurchase of Shares Proceeds from Issuance of Common Stock Under Stock-Based Employee Compensation Plans Equity securities, Cost Payments to Acquire Property, Plant, and Equipment Purchases of Property and Equipment, Net Purchases of Property and Equipment, Net Purchases of Property and Equipment, Net Purchases of Property and Equipment, Net Segments Information Federal and Foreign Income Tax Purchases of Fixed Maturities Fixed Maturities Abstract Fixed Maturities [Abstract] Fixed Maturities Shareholders' Equity Shareholders' Equity Liabilities Abstract Liabilities [Abstract] Liabilities Assets Abstract Assets [Abstract] Assets Earnings Per Share [Abstract] Revenues Abstract Revenues [Abstract] Revenues Other Comprehensive Income (Loss), Net of Tax Cash Flows from Investing Activities Cash Flows from Financing Activities Cash Flows from Operating Activities Short Term Investments Equity Securities (cost $1,660 and $1,907) Equity securities Equity securities, Fair value Equity Securities (cost $1,253 and $1,215) Accrued Expenses and Other Liabilities Accrued Expenses and Other Liabilities Accrued Expenses and Other Liabilities Losses and Loss Expenses Other Insurance Operating Costs and Expenses Proceeds From Sale Of Available For Sale Securities, Debt Proceeds from Fixed Maturities - Sales Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities Proceeds from Fixed Maturities - Maturities, Calls and Redemptions Segments Information [Abstract] Entity Common Stock, Shares Outstanding (actual number of shares) Proceeds from Sales of Equity Securities Proceeds from Sale of Available-for-sale Securities, Equity Federal and Foreign Income Tax Income Tax Expense (Benefit) Long Term Debt Long-term Debt Retained Earnings Retained Earnings (Accumulated Deficit), Beginning Balance Retained Earnings (Accumulated Deficit), Ending Balance Retained Earnings (Accumulated Deficit) Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance Accumulated Other Comprehensive Income (Loss), Net of Tax Net Income Proceeds from Issuance of Common Stock Under Stock-Based Employee Compensation Plans Unpaid Losses and Loss Expenses Liability for Claims and Claims Adjustment Expense, Property Casualty Liability Paid-In Surplus Additional Paid in Capital, Total Additional Paid in Capital, Beginning Balance Additional Paid in Capital, Ending Balance Additional Paid in Capital Investments in Other Invested Assets, Net Payments for (Proceeds from) Limited Partnership Increase in Short Term Investments, Net Payments for (Proceeds from) Short-term Investments, Total Payments for (Proceeds from) Short-term Investments Change In Net Payable Receivable From Security Transactions Not Settled Increase in Net Payable from Security Transactions Not Settled Increase in Net Payable from Security Transactions Not Settled Increase (Decrease) in Net Payable from Security Transactions Not Settled Change in net receivable or payable from security transactions not settled. Premiums Earned, Net, Property and Casualty Total Premiums Earned Premiums Earned, Net, Property and Casualty, Total Premiums Earned Corporate Expenses TOTAL INVESTED ASSETS Investments Increase in Unpaid Losses and Loss Expenses, Net Increase (Decrease) in Property and Casualty Insurance Liabilities Proceeds from Issuance of Common Stock Under Stock-Based Employee Compensation Plans Increase in Short Term Investments, Net Purchases of Fixed Maturities Purchases of Equity Securities Repurchase of Shares Common Stock, Shares Issued Common Stock, Shares, Outstanding, Total Treasury Stock, Shares Treasury Stock, Shares, Beginning Balance Treasury Stock, Shares, Ending Balance Investments in Other Invested Assets, Net Accrued Investment Income Accrued Investment Income Receivable, Total Premiums Receivable Premiums Receivable, at Carrying Value, Total Reinsurance Recoverable on Unpaid Losses and Loss Expenses Prepaid Reinsurance Premiums Deferred Policy Acquisition Costs Deferred Policy Acquisition Costs, Total Goodwill Goodwill, Beginning Balance Goodwill, Ending Balance Unearned Premiums Unearned Premiums, Total Cash Flows from Operating Activities Depreciation Cash Flows from Investing Activities Purchases of Fixed Maturities Purchases of Equity Securities Repurchase of Shares Short Term Investments Losses and Loss Expenses Amortization of Deferred Policy Acquisition Costs Deferred Policy Acquisition Cost, Amortization Expense, Total Other Insurance Operating Costs and Expenses Investment Expenses Other Expenses Other Nonoperating Expense, Total Net Income Per Share Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Commitments and Contingencies Contingent Liabilities (Note 6) Cash Flows from Financing Activities Other Comprehensive Income (Loss), Net of Tax Common Stock, Par Value Change In Unrealized Other Than Temporary Impairments Of Investments This item represents the non-credit impairment losses portion of other-than-temporary impairments on fixed maturity investments in which a credit loss was recognized in the Consolidated Statements of Income. This item includes the impact of subsequent changes to these securities such as appreciation or loss in value or subsequent sale of the security. Realized Gains Losses Net Abstract Realized Investment Gains (Losses), Net Other Realized Gains Losses Net Other Realized Investment Gains, Net Other Realized Investment Gains (Losses), Net This item represents the net total realized gain (loss) included in earnings for the period as a result of selling or holding invested assets. Total Realized Gains (Losses), Net Total Other-than-Temporary Impairment Losses on Investments Total Realized Gains (Losses), Net Earnings Per Share Earnings Per Share [Text Block] Other Than Temporary Impairment Losses on Investments Recognized In Other Comprehensive Income Other-Than-Temporary Impairment Losses on Investments Recognized in Other Comprehensive Income Other-than-Temporary Impairment Losses on Investments Recognized in Other Comprehensive Income This item represents the non-credit impairment loss portion of the total other-than-temporary impairment losses on investments for fixed maturity investments that the Corporation does not intend to sell or it is not more likely than not the Corporation will be required to sell these securities before they recover to their amortized cost value. This amount offsets the amount included in the total other-than-temporary impairment losses on investments and recognized in accumulated other comprehensive income. Dividend Payable to Shareholders Dividends Payable Total Other-Than-Temporary Impairment Losses on Investments Segments Information Losses and Expenses [Abstract] Losses and Expenses Consolidated Statements of Comprehensive Income Consolidated Statements of Comprehensive Income Consolidated Statements of Comprehensive Income Increase Decrease In Funds Held Under Reinsurance Agreements Increase in Funds Held Under Deposit Contracts Increase in Funds Held Under Deposit Contracts Change in Unrealized Other-Than-Temporary Impairments of Investments Change in Unrealized Other-Than-Temporary Impairments Losses on Investments Change in Unrealized Other-Than-Temporary Impairment Losses on Investments Available For Sale Securities In Unrealized Loss Position [Axis] Available For Sale Securities In Unrealized Loss Position. Available For Sale Securities In Unrealized Loss Position [Domain] Available For Sale Securities In Unrealized Loss Position. Fixed Maturities and Equity Securities In Unrealized Loss Position [Member] Fixed maturities And equity securities in an unrealized loss position as of the reporting date. Length of time in unrealized loss position [Axis] Length of time in unrealized loss position. Length of time in unrealized loss position [Domain] Length of time in unrealized loss position. U.S. Government and government agency and authority obligations [Member] Fair Values of Financial Instruments [Abstract] No definition available. Fair Value Disclosures [Text Block] Fair Values of Financial Instruments Amortized Cost And Fair Value Of Invested Assets Abstract Amortized cost and fair value of fixed maturities and equity securities [Abstract] Gross Gain Loss Otti Equity Securities Total Total equity securities The total gross realized gain or loss, net, for equity securities included in earnings for the period. Personal insurance [Member] Commercial insurance [Member] Property and Casualty Insurance [Axis] Property And Casualty Insurance Axis. Property and Casualty Insurance [Domain] Property And Casualty Insurance Domain. Income (loss) before income tax [Abstract] No definition available. Income (loss) before income tax [Abstract] Gross Gain Loss Otti Total Fixed Maturities Total fixed maturities The total gross realized gain or loss, net, for fixed maturities included in earnings for the period. Other Comprehensive Income, Foreign Currency Transaction and Translation Adjustment, Net of Tax Foreign Currency Translation Gains (Losses) Foreign currency translation gains (losses), Net of tax Foreign Currency Translation Gains (Losses) Foreign Currency Translation Losses Fair Values Of Fixed Maturities And Equity Securities Based Upon Lowest Level Of Input [Text Block] Fair values of fixed maturities and equity securities categorized based upon the lowest level of input This table discloses the fair value of fixed maturities and equity securities categorized based upon the lowest level of input that was significant to the fair value measurement. Fair Values Of Fixed Maturities And Equity Securities Based Upon Lowest Level Of Input Abstract Fair values of fixed maturities and equity securities categorized based upon the lowest level of input [Abstract] No definition available. Other Comprehensive Income, Available-for-sale Securities Adjustment, Net of Tax Other Comprehensive Income, Available-for-sale Securities Adjustment, Net of Tax, Total Change in Unrealized Appreciation of Investments General (Policies) [Abstract] Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] General Accounting Pronouncements Not Yet Adopted [Abstract] No definition available. Available-for-sale Securities [Text Block] Invested Assets Commitments and Contingencies Disclosure [Text Block] Contingent Liabilities Common Stock, Dividends, Per Share, Declared Dividends Declared Per Share Invested Assets [Abstract] No definition available. Invested Assets (Details) [Abstract] Invested Assets. Invested Assets (Tables) [Abstract] No definition available. Contingent Liabilities [Abstract] No definition available. Revenues Income Before Income Tax Of Each Operating Segment [Text Block] Revenues and income before income tax of each operating segment A table disclosing revenues and income before income tax of each operating segment.