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Segment Information (Income From Continuing Operations, Before Federal Income Tax) (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013
Segment Reporting Information [Line Items] |  |  |  |
Net investment income earned | $ 34,292 | $ 32,457 | $ 106,600 | $ 99,330
Net realized investment gains | 15,231 | 13,431 | 26,988 | 21,940
Total investment revenues | 49,523 | 45,888 | 133,588 | 121,270
Tax on investment income | 13,858 | 12,648 | 36,374 | 31,960
Total investment income after federal income tax | 35,665 | 33,240 | 97,214 | 89,310
Total Standard Commercial Lines [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Underwriting gain (loss), before federal income tax | 27,771 | 8,776 | 39,844 | 24,621
Total Standard Personal Lines [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Underwriting gain (loss), before federal income tax | 8,037 | 1,362 | 95 | 4,360
Total Standard Insurance Operations [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Underwriting gain (loss), before federal income tax | 35,808 | 10,138 | 39,939 | 28,981
GAAP combined ratio | 91.60% | 97.50% | 96.90% | 97.60%
Statutory combined ratio | 90.50% | 96.00% | 96.30% | 96.60%
Excess And Surplus Operations [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Underwriting gain (loss), before federal income tax | $ (1,371) | $ 13 | $ (433) | $ (2,186)
GAAP combined ratio | 103.80% | 100.00% | 100.40% | 102.40%
Statutory combined ratio | 102.90% | 100.50% | 100.30% | 101.90%

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- Definition The statutory combined ratio (expressed as a percentage) is the sum of: (i) the loss and loss expense ratio; (ii) the underwriting ratio; and (iii) the dividend ratio. The loss and loss expense ratio as well as the dividend ratio is calculated by dividing loss and loss expenses, as well as dividends to policyholders, by net premiums earned. The underwriting expense ratio is calculated by dividing underwriting expenses by net premiums written. + References No definition available. + Details
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- Definition Taxes paid on investment income + References No definition available. + Details
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- Definition The income earned from investments in securities and other investments including dividends, interest, and returns on other investments, including realized gains/losses, after-tax + References No definition available. + Details
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- Definition The income earned from investments in securities and other investments including dividends, interest, and returns on other investments, including realized gains/losses. + References No definition available. + Details
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- Definition Net premiums earned and other insurance income less net loss and loss expenses incurred, loss adjustment expenses, policy acquisition costs and other underwriting expenses. + References No definition available. + Details
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- Definition Ratio of non-life losses and loss expenses, non-life acquisition expenses and non-life general and administrative expenses, to non-life net premiums earned. + References No definition available. + Details
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- Definition Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 16 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.2) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 2 -Article 7 + Details
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- Definition The net realized gains or losses on investments during the period, not including gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.3(a)) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 325 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6485959&loc=d3e22529-158502 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 3 -Subparagraph a -Article 7 + Details
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