XML 38 R3.htm IDEA: XBRL DOCUMENT ﻿
v2.3.0.11

Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data | Jun. 30, 2011 | Dec. 31, 2010
--- | --- | ---
Statement of Consolidated Balance Sheets |  |
Fixed maturity securities, held-to-maturity, fair value | $ 1,120,977 | $ 1,256,294
Fixed maturity securities, available-for-sale, amortized cost | 2,442,579 | 2,285,988
Equity securities, available-for-sale, cost | 128,187 | 58,039
Premiums receivable, allowance for uncollectible accounts | 4,054 | 4,691
Property and equipment, accumulated depreciation and amortization | $ 156,209 | $ 151,704
Preferred stock, par value per share | $ 0 | $ 0
Preferred stock, shares authorized | 5,000,000 | 5,000,000
Preferred stock, shares issued | 0 | 0
Preferred stock, shares outstanding | 0 | 0
Common stock, par value per share | $ 2 | $ 2
Common stock, shares authorized | 360,000,000 | 360,000,000
Common stock, shares issued | 96,987,900 | 96,362,667
Treasury stock, shares | 42,823,108 | 42,686,204

X
- Definition This item represents the aggregate cost of investments in equity securities as of the balance sheet date and which are not categorized as trading, net of adjustments for other-than-temporary impairments. + Details
Name: | sigi_EquitySecuritiesAvailableForSaleCost
Namespace Prefix: | sigi
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 -Subparagraph c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 14 -Article 5 + Details
Name: | us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Namespace Prefix: | us-gaap
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition This item represents the total of all debt securities grouped by maturity dates, at cost, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, which are classified neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 7 -Footnote 2 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 20 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCost
Namespace Prefix: | us-gaap
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Face amount or stated value of common stock per share; generally not indicative of the fair market value per share. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 + Details
Name: | us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap
Data Type: | us-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum number of common shares permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 + Details
Name: | us-gaap_CommonStockSharesAuthorized
Namespace Prefix: | us-gaap
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition This item represents the aggregate fair value of investments in debt securities as of the balance sheet date and which are categorized as held-to-maturity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 19 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 137 + Details
Name: | us-gaap_HeldToMaturitySecuritiesFairValue
Namespace Prefix: | us-gaap
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Face amount or stated value per share of nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer); generally not indicative of the fair market value per share. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 2, 3, 4, 5, 6, 7, 8 + Details
Name: | us-gaap_PreferredStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap
Data Type: | us-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 2, 3, 4, 5, 6, 7, 8 + Details
Name: | us-gaap_PreferredStockSharesAuthorized
Namespace Prefix: | us-gaap
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 + Details
Name: | us-gaap_PreferredStockSharesIssued
Namespace Prefix: | us-gaap
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 + Details
Name: | us-gaap_PreferredStockSharesOutstanding
Namespace Prefix: | us-gaap
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The carrying value as of the balance sheet date of the estimated valuation allowance to reduce gross premiums receivable to net realizable value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 114 -Paragraph 20 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 09 -Article 12 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 01-6 -Paragraph 13 -Subparagraph e Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 5 -Paragraph 9 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 5 -Article 7 + Details
Name: | us-gaap_PremiumsReceivableAllowanceForDoubtfulAccounts
Namespace Prefix: | us-gaap
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_StatementOfFinancialPositionAbstract
Namespace Prefix: | us-gaap
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 + Details
Name: | us-gaap_TreasuryStockShares
Namespace Prefix: | us-gaap
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant