XML 64 R63.htm IDEA: XBRL DOCUMENT v2.3.0.15

Commitments and Contingencies (Narrative) (Details) (Other Investments [Member], USD $) In Thousands	Sep. 30, 2011
Other Investments [Member]
Remaining Commitment	$ 60,657

X

- Definition

This item represents contractual obligations to invest additional amounts on our other investment portfolio. These additional investments may or may not be required.

+ Details

Name:	sigi_RemainingCommitment
Namespace Prefix:	sigi
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant