XML 61 R111.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Share-Based Payments (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Stock Issued During Period Shares | 862,662 | 857,403 | 783,661
Number of options granted | 0 |  |
Stock Issued During Period Shares Dividend Reinvestment Plan | 63,349 | 90,110 | 100,383
Expense charged | $ 19.9 | $ 13.8 | $ 10.1
Corresponding income tax benefit | 6.8 | 4.8 | 3.5
Omnibus Stock Plan [Member] |  |  |
Maximum exercise period for an option grant | 10 years |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized | 4,233,305 |  |
Number of shares available in reserve | 3,445,663 |  |
DEUs accrued | 23,505 | 32,558 | 41,469
DEU issuances | 39,296 | 48,224 | 33,532
Cash Incentive Plan [Member] |  |  |
Cash units granted, net of forfeiture | 55,365 | 46,961 | 46,879
Stock Option II [Member] |  |  |
Maximum exercise period for an option grant | 10 years |  |
Number of shares available in reserve | 298,680 |  |
Stock Option III [Member] |  |  |
Maximum exercise period for an option grant | 10 years |  |
Number of shares available in reserve | 275,244 |  |
Stock Option Plan For Directors [Member] |  |  |
Number of shares available in reserve | 114,000 |  |
Stock Compensation Plan For Non Employee Directors [Member] |  |  |
Number of shares available in reserve | 94,290 |  |
Employee Stock Purchase Plan [Member] |  |  |
Stock Issued During Period Shares | 122,951 | 129,081 | 131,705
Number of shares available in reserve | 870,930 |  |
Discount from market price, offering date | 85.00% |  |
Discount from market price, purchase date | 85.00% |  |
Agent Stock Purchase Plan [Member] |  |  |
Stock Issued During Period Shares | 86,388 | 89,723 | 111,427
Number of shares available in reserve | 2,098,020 |  |
Discount from market price, purchase date | 10.00% |  |
Expense charged | 0.2 | 0.2 | 0.2
Corresponding income tax benefit | $ 0.1 | $ 0.1 | $ 0.1
Restricted Stock Units (RSUs) [Member] | Omnibus Stock Plan [Member] |  |  |
Number of restricted stock units granted net of forfeitures | 376,163 | 326,213 | 402,925
Stock Option [Member] | Stock Option Plan For Directors [Member] |  |  |
Number of options granted | 6,000 |  |

X
- Definition Number of units granted during the period as a result of a liablity share-based compensation plan, net of any shares forfeited. + References No definition available. + Details
Name: | sigi_CashUnitsGrantedDuringPeriodShareBasedCompensation
Namespace Prefix: | sigi_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Gross number of accrued dividend equivalent units ("DEUs") during the period. DEUs are earned on restricted stock units and are reinvested in the Parent's common stock at fair value on each dividend payment date. + References No definition available. + Details
Name: | sigi_DividendEquivalentUnitsShareBasedCompensationAccrued
Namespace Prefix: | sigi_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of issued dividend equivalent units ("DEUs") during the period. DEUs are earned on restricted stock units and are reinvested in the Parent's common stock at fair value on each dividend payment date. + References No definition available. + Details
Name: | sigi_DividendEquivalentUnitsShareBasedCompensationIssued
Namespace Prefix: | sigi_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum exercise period for an option grant as specified in the award agreement. + References No definition available. + Details
Name: | sigi_MaximumExercisePeriodForOptionGrant
Namespace Prefix: | sigi_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 14.F) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 14 -Section F + Details
Name: | us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Discount rate from fair value on offering date that participants pay for shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Discount rate from fair value on purchase date that participants pay for shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net number of non-option equity instruments granted to participants. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Gross number of share options (or share units) granted during the period. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares issued during the period from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the shareholders to reinvest dividends paid to them by the entity on new issues of stock by the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of any shares forfeited. Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 4: 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_StockIssuedDuringPeriodSharesShareBasedCompensation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration