XML 152 R122.htm IDEA: XBRL DOCUMENT v3.22.0.1

Commitments and Contingencies (Narrative) (Details) $ in Thousands	Dec. 31, 2021 USD ($)
Total contractually obligated investments
Contractual Obligation Additional Investment in Alternative or Other Investments	$ 288,800
Alternative and Other Investments
Contractual Obligation Additional Investment in Alternative or Other Investments	215,000
Non-publicly traded collateralized loan obligations in our fixed income securities portfolio
Contractual Obligation	59,800
Non-publicly traded common stock within our equity portfolio
Contractual Obligation	4,200
Commercial Mortgage Loans SIGI
Contractual Obligation	5,500
Privately placed corporate securities
Contractual Obligation	$ 4,300

X

- Definition

Contractual obligation to invest additional amounts in alternative and other investments.

+ References

No definition available.

+ Details

Name:	sigi_ContractualObligationAdditionalInvestmentinAlternativeorOtherInvestments
Namespace Prefix:	sigi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

+ References

No definition available.

+ Details

Name:	us-gaap_ContractualObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_InvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_OtherAggregatedInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_CollateralizedLoanObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=sigi_CommercialMortgageLoansSIGIMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=sigi_PrivatePlacementCorporateSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: