v3.25.4

Equity - Share Repurchase Program (Details) - USD ($)	12 Months Ended
Equity - Share Repurchase Program (Details) - USD ($)	Dec. 31, 2025	Dec. 31, 2024	Oct. 22, 2025	Dec. 02, 2020
Share Repurchase Program [Line Items]
Number of shares repurchased (in shares)	1,093,385	103,000
Total cost of shares repurchased	$ 85,600,000	$ 8,700,000
Share repurchase program, remaining authorized, amount	$ 170,000,000.0	$ 75,500,000
Prior Share Repurchase Program
Share Repurchase Program [Line Items]
Share repurchase program, authorized, amount				$ 100,000,000
Number of shares repurchased (in shares)	698,312
Total cost of shares repurchased	$ 55,600,000
Share repurchase program, remaining authorized, amount	$ 0
Current Share Repurchase Program
Share Repurchase Program [Line Items]
Share repurchase program, authorized, amount			$ 200,000,000
Number of shares repurchased (in shares)	395,073
Total cost of shares repurchased	$ 30,000,000.0
Share repurchase program, remaining authorized, amount	$ 170,000,000.0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481520/505-30-50-4

+ Details

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- Definition

Amount authorized for purchase of share under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership.

+ References

+ Details

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- Definition

Amount remaining authorized for purchase of share under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership.

+ References

No definition available.

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- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

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- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

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-SubTopic 30
-Section 45
-Paragraph 1
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-URI https://asc.fasb.org/1943274/2147481549/505-30-45-1

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SELECTIVE INSURANCE GROUP INC 10-K