v3.25.3

Investments - Equity Securities without Readily Determinable Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Initial cost	$ 82.6	$ 74.8
Cumulative upward adjustments	54.7	57.9
Cumulative downward adjustments (including impairments)	(22.9)	(24.4)
Carrying value	$ 114.4	$ 108.3

Equity Securities without Readily Determinable Fair Value, Downward Price Adjustment And Impairment Loss, Cumulative Amount

+ References

No definition available.

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- Definition

Equity Securities without Readily Determinable Fair Value, Initial Cost

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No definition available.

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- Definition

Amount of investment in equity security without readily determinable fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 321
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479536/321-10-50-3

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- Definition

Amount of cumulative gain from upward price adjustment on investment in equity security without readily determinable fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 321
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479536/321-10-50-3

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- References

No definition available.

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ASSURANT, INC. 10-Q