Document and Entity Information [Abstract] Document And Entity Information. Consolidated Statements of Earnings and Comprehensive Income [Abstract] Revenues Revenues [Abstract] Costs and expenses Benefits, Losses and Expenses [Abstract] Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other comprehensive income Earnings Per Share, Diluted Diluted earnings per share Earnings Per Share, Basic Basic earnings per share Net Income (Loss) Attributable to Parent Net earnings Net earnings Comprehensive Income, Net of Tax, Attributable to Parent Comprehensive income Other Other comprehensive income (loss), other than that arising from changes in unrealized appreciation of investment securities during the period being reported on. Other Other Comprehensive Income, Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax Less: reclassification for net realized capital gains and other than temporary impairment losses, net of taxes Other Comprehensive Income, Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Change in unrealized gains (losses), net of deferred taxes Income taxes Income Tax Expense (Benefit) Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Cumulative Effects of Changes in Accounting Principles, Noncontrolling Interest Earnings before income taxes Total costs and expenses Benefits, Losses and Expenses Interest expense Interest Expense General and Administrative Expense Corporate administration Other Cost and Expense, Operating Other operating expenses Total revenues Revenues Other income Other Income Other than temporary impairment losses Impairment of Investments Net Investment Income Net investment income Premiums Earned, Net Net premiums earned Other than temporary impairment losses Consolidated Balance Sheets [Abstract] Assets [Abstract] Assets Investments Investments [Abstract] Available-for-sale securities at fair value: Available-for-sale Securities [Abstract] Liabilities and Stockholders' Equity Liabilities and Stockholders' Equity [Abstract] Total liabilities and stockholders' equity Liabilities and Stockholders' Equity Stockholders' Equity Attributable to Parent Ending Balance Beginning Balance Total stockholders' equity Retained Earnings (Accumulated Deficit) Retained earnings Treasury stock, at cost (2011 - 364,793 shares; 2010 - 351,532 shares) Treasury Stock, Value Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive income Common stock (shares authorized: 2011 and 2010 - 22,000,000; issued and outstanding 2011 - 9,300,143; 2010 - 9,300,448) Common Stock, Value, Issued Total liabilities Liabilities Other liabilities Other Liabilities Current taxes payable Accrued Income Taxes, Current Reinsurance payable Reinsurance Payable Unearned Premiums Unearned premiums Reserve for Losses and Loss Adjustment Expenses Loss and loss adjustment expenses Total assets Assets Other Assets Other assets Deferred Tax Assets, Net Net deferred tax assets Goodwill And Other Intangibles Net Of Amortization Goodwill and other intangibles, net of amortization Goodwill and other intangibles, net of amortization. Property, Plant and Equipment, Net Property and equipment at cost, net of accumulated depreciation and amortization Deferred Policy Acquisition Costs Deferred acquisition costs Ceded unearned premium reserves Prepaid Reinsurance Premiums Reinsurance Recoverables Reinsurance recoverables Premiums Receivable, at Carrying Value Premium balances receivable Total investments Investments Other invested assets Other Investments Debt securities (amortized cost: 2011 - $2,783,146; 2010 - $2,778,117) Available-for-sale Securities, Debt Securities Equity securities (cost: 2011 - $1,284,686; 2010 - $1,310,009) Available-for-sale Securities, Equity Securities Consolidated Statements of Cash Flows [Abstract] Cash Paid During The Period For Abstract Cash paid during the period for: Cash paid during the period for. Income Taxes Paid, Net Income taxes paid (refunds received) Interest Paid, Net Interest Supplemental disclosures of cash flow information Supplemental Cash Flow Information [Abstract] Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net earnings to net cash provided by operating activities: Cash and Cash Equivalents, Period Increase (Decrease) Net cash increase (decrease) in cash Net Cash Provided by (Used in) Financing Activities Net cash (used in) provided by financing activities Other, net Proceeds from (Payments for) Other Financing Activities Payments for Repurchase of Common Stock Treasury stock acquisitions Net Cash Provided by (Used in) Investing Activities Net cash (used in) provided by investing activities Payments for (Proceeds from) Other Investing Activities Other, net Payments for (Proceeds from) Short-term Investments Net change in short-term investments Payments to Acquire Property, Plant, and Equipment Purchases of property and equipment Maturities of investments Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities Proceeds from Sale of Available-for-sale Securities Sales of investments Payments to Acquire Available-for-sale Securities Purchase of investments Net Cash Provided by (Used in) Operating Activities Net cash (used in) provided by operating activities Net adjustments Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities Increase (Decrease) in Loss and Loss Adjustment Expense Reserve Increase (decrease) in loss and loss adjustment expenses Increase (decrease) in unearned premiums Increase (Decrease) in Unearned Premiums Increase (Decrease) in Deferred Policy Acquisition Costs (Increase) decrease in deferred acquisition costs Increase (Decrease) in Prepaid Reinsurance Premiums (Increase) decrease in ceded unearned premium reserves Increase (Decrease) in Premiums Receivable (Increase) decrease in premium balances receivable Increase (Decrease) in Reinsurance Recoverable (Increase) decrease in reinsurance receivable, net of reinsurance payable Increase (Decrease) in Other Operating Assets (Increase) decrease in other assets Depreciation, Depletion and Amortization, Nonproduction Depreciation and amortization Common stock, shares issued Common Stock, Shares, Issued, Total Common Stock, Shares, Issued Common stock, shares authorized Common Stock, Shares Authorized Cost Of Equity Securities Cost of equity securities Cost of equity securities. Entity Registrant Name Entity Central Index Key Document Type Document Period End Date Amendment Flag 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 Principles of Financial Statement Presentation [Abstract] Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Principles of Financial Statement Presentation Earnings Per Share of Common Stock [Abstract] Earnings Per Share of Common Stock Earnings Per Share [Text Block] Commitments and Contingencies [Abstract] Commitments and Contingencies. Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Segment Reporting Disclosure [Text Block] Segments of Business Reinsurance [Abstract] Reinsurance Reinsurance [Text Block] Income Taxes [Abstract] Income Taxes Income Tax Disclosure [Text Block] Short-term investments Cash Cash Amortized cost for debt securities Available-for-sale Securities, Debt Maturities, Amortized Cost, Total Available-for-sale Securities, Debt Maturities, Amortized Cost Realized Investment Gains (Losses) Net realized capital (gains) losses Net realized capital gains Cash at beginning of period Cash at end of period Liabilities and Stockholders' Equity Short-term Investments Increase (Decrease) in Accrued Liabilities Increase (decrease) in other liabilities and current taxes Total investment in equity and debt Marketable Securities Document Fiscal Year Focus Document Fiscal Period Focus Segments of Business [Abstract] Segments of Business. Additional Paid in Capital, Common Stock Contributed capital Incurred Claims, Property, Casualty and Liability Loss and loss adjustment expenses Expense Related to Distribution or Servicing and Underwriting Fees Commissions, brokerage and other underwriting expenses Long-term Debt Senior Notes Common Stock, Shares, Outstanding Common Stock, Shares, Outstanding, Ending Balance Common Stock, Shares, Outstanding, Beginning Balance Common stock, shares outstanding Common stock, shares outstanding Treasury Stock, Shares Treasury Stock, Shares, Ending Balance Treasury Stock, Shares, Beginning Balance Treasury stock, shares Treasury stock, shares Available-for-sale Securities [Text Block] Investments Recent Accounting Standards [Abstract] Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Recent Accounting Standards