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Organization | 12 Months Ended
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Dec. 31, 2011
Organization [Abstract] |
Organization | Note 1. Organization Selective Insurance Group, Inc., through its subsidiaries, (collectively referred to as "we," "us," or "our") offers standard and excess and surplus lines ("E&S") property and casualty insurance products. Selective Insurance Group, Inc. (referred to as the "Parent") was incorporated in New Jersey in 1977 and its main offices are located in Branchville, New Jersey. The Parent's common stock is publicly traded on the NASDAQ Global Select Market under the symbol "SIGI." We have provided a glossary of terms as Exhibit 99.1 to this Form 10-K, which defines certain industry-specific and other terms that are used in this Form 10-K. In August 2011, we purchased the renewal rights to an E&S book of business and, effective as of December 31, 2011, we purchased Montpelier U.S. Insurance Company ("MUSIC") which is now our eighth insurance subsidiary. Our eight insurance subsidiaries are collectively referred to as the "Insurance Subsidiaries". MUSIC, an E&S carrier, is authorized to write business in all 50 states and the District of Columbia, and provides us with a nationally-licensed platform to write contract binding authority E&S business. We classify our business into two operating segments: Insurance Operations, which sells property and casualty insurance products and services in both the standard and E&S markets; and Investments, which invests the premiums collected by our insurance operations.

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- Definition The entire disclosure for the nature of an entity's business, the major products or services it sells or provides and its principal markets, including the locations of those markets. If the entity operates in more than one business, the disclosure also indicates the relative importance of its operations in each business and the basis for the determination (for example, assets, revenues, or earnings). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Name Statement of Position (SOP) -Publisher AICPA -Number 94-6 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6003-108592 + Details
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