XML 57 R75.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Fair Value Measurements (Carrying Value and Estimated Fair Value of Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013
--- | --- | ---
Held-to-maturity Securities | $ 318,137 us-gaap_HeldToMaturitySecurities | $ 392,879 us-gaap_HeldToMaturitySecurities
Available-for-sale Securities, Debt Securities | 4,066,122 us-gaap_AvailableForSaleSecuritiesDebtSecurities | 3,715,536 us-gaap_AvailableForSaleSecuritiesDebtSecurities
Equity securities, AFS | 191,400 us-gaap_AvailableForSaleSecuritiesEquitySecurities | 192,771 us-gaap_AvailableForSaleSecuritiesEquitySecurities
Short-term investments | 131,972 us-gaap_OtherShortTermInvestments | 174,251 us-gaap_OtherShortTermInvestments
Notes payable | 379,297 us-gaap_LongTermDebt | 392,414 us-gaap_LongTermDebt
Carrying Amount [Member] |  |
Held-to-maturity Securities | 318,137 us-gaap_HeldToMaturitySecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember | 392,879 us-gaap_HeldToMaturitySecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember
Available-for-sale Securities, Debt Securities | 4,066,122 us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember | 3,715,536 us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember
Equity securities, AFS | 191,400 us-gaap_AvailableForSaleSecuritiesEquitySecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember | 192,771 us-gaap_AvailableForSaleSecuritiesEquitySecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember
Short-term investments | 131,972 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember | 174,251 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember
Notes payable | 379,297 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember | 392,414 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember
Carrying Amount [Member] | Two Point Ninety Percent Borrowing From Federal Home Loan Bank [Member] |  |
Notes payable | 0 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_TwoPointNinetyPercentBorrowingFromFederalHomeLoanBankMember | 13,000 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_TwoPointNinetyPercentBorrowingFromFederalHomeLoanBankMember
Carrying Amount [Member] | One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member] |  |
Notes payable | 45,000 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_OnePointTwentyFivePercentBorrowingFromFederalHomeLoanBankMember | 45,000 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_OnePointTwentyFivePercentBorrowingFromFederalHomeLoanBankMember
Carrying Amount [Member] | Seven Point Twenty Five Percent Senior Notes [Member] |  |
Notes payable | 49,896 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_SevenPointTwentyFivePercentSeniorNotesMember | 49,916 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_SevenPointTwentyFivePercentSeniorNotesMember
Carrying Amount [Member] | Six Point Seventy Percent Senior Notes [Member] |  |
Notes payable | 99,401 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_SixPointSeventyPercentSeniorNotesMember | 99,498 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_SixPointSeventyPercentSeniorNotesMember
Carrying Amount [Member] | Five Point Eight Hundred Seventy Five [Member] |  |
Notes payable | 185,000 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_FivePointEightHundredSeventyFiveMember | 185,000 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_FivePointEightHundredSeventyFiveMember
Fair Value [Member] |  |
Held-to-maturity Securities | 333,961 us-gaap_HeldToMaturitySecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember | 416,981 us-gaap_HeldToMaturitySecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
Available-for-sale Securities, Debt Securities | 4,066,122 us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember | 3,715,536 us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
Equity securities, AFS | 191,400 us-gaap_AvailableForSaleSecuritiesEquitySecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember | 192,771 us-gaap_AvailableForSaleSecuritiesEquitySecurities / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
Short-term investments | 131,972 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember | 174,251 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
Notes payable | 404,270 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember | 354,010 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
Fair Value [Member] | Two Point Ninety Percent Borrowing From Federal Home Loan Bank [Member] |  |
Notes payable | 0 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_TwoPointNinetyPercentBorrowingFromFederalHomeLoanBankMember | 13,319 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_TwoPointNinetyPercentBorrowingFromFederalHomeLoanBankMember
Fair Value [Member] | One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member] |  |
Notes payable | 45,244 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_OnePointTwentyFivePercentBorrowingFromFederalHomeLoanBankMember | 45,259 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_OnePointTwentyFivePercentBorrowingFromFederalHomeLoanBankMember
Fair Value [Member] | Seven Point Twenty Five Percent Senior Notes [Member] |  |
Notes payable | 59,181 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_SevenPointTwentyFivePercentSeniorNotesMember | 50,887 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_SevenPointTwentyFivePercentSeniorNotesMember
Fair Value [Member] | Six Point Seventy Percent Senior Notes [Member] |  |
Notes payable | 114,845 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_SixPointSeventyPercentSeniorNotesMember | 98,247 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_SixPointSeventyPercentSeniorNotesMember
Fair Value [Member] | Five Point Eight Hundred Seventy Five [Member] |  |
Notes payable | $ 185,000 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_FivePointEightHundredSeventyFiveMember | $ 146,298 us-gaap_LongTermDebt / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_LongtermDebtTypeAxis = sigi_FivePointEightHundredSeventyFiveMember

X
- Definition Amount of debt securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 2 -Subparagraph (b)-(g) -URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of equity securities categorized neither as held-to-maturity nor as trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803 + Details
Name: | us-gaap_AvailableForSaleSecuritiesEquitySecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.6) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_HeldToMaturitySecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20, 22 -Article 5 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Other investments not otherwise specified in the taxonomy that will be realized in a short period of time, usually less than one year or the normal operating cycle, whichever is longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.8) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.5) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(g)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 5 -Article 9 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph g -Article 7 + Details
Name: | us-gaap_OtherShortTermInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |