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Segment Information (Income From Continuing Operations, Before Federal Income Tax) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Net investment income earned	$ 36,774	$ 34,003	$ 72,308	$ 66,873
Net realized investment gains	4,539	5,154	11,757	8,509
Total investment revenues	41,313	39,157	84,065	75,382
Tax on investment income	10,941	10,107	22,516	19,312
Total Investment Income After Federal Income Tax	30,372	29,050	61,549	56,070
Total Standard Commercial Lines [Member]
Segment Reporting Information [Line Items]
Underwriting gain (loss), before federal income tax	15,703	9,743	12,073	15,845
Total Standard Personal Lines [Member]
Segment Reporting Information [Line Items]
Underwriting gain (loss), before federal income tax	(5,582)	(2,975)	(7,942)	2,998
Total Standard Insurance Operations [Member]
Segment Reporting Information [Line Items]
Underwriting gain (loss), before federal income tax	10,121	6,768	4,131	18,843
GAAP combined ratio	97.60%	98.30%	99.50%	97.60%
Statutory combined ratio	97.30%	97.00%	99.20%	96.90%
Excess And Surplus Operations [Member]
Segment Reporting Information [Line Items]
Underwriting gain (loss), before federal income tax	$ (37)	$ (2,285)	$ 938	$ (2,199)
GAAP combined ratio	100.10%	107.60%	98.60%	103.70%
Statutory combined ratio	99.90%	106.80%	98.80%	102.60%

X

- Definition

The income earned from investments in securities and other investments including dividends, interest, and returns on other investments. This item does not include realized gains (losses).

+ References

No definition available.

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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.

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- Definition

Taxes paid on investment income

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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.

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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

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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.

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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.

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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

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