Derivatives - Fair Value of Derivatives Included in Consolidated Statements of Operations (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Derivative [Line Items]
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net investment losses	Net investment losses	Net investment losses
Change in fair value of derivatives:
Net investment gains (losses)	$ 2.1	$ 1.0	$ 7.4
Sales
Change in fair value of embedded derivatives:
Net investment gains (losses)	$ (14.5)	$ (9.5)	$ (7.2)

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4A

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-SubTopic 10
-Topic 825
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482881/825-10-55-10

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Indicates line item in statement of income or comprehensive income that includes gain (loss) from derivative.

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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 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480682/815-20-25-6A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-5

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Net Increase or Decrease in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4A

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 15
-Name Accounting Standards Codification
-Section 25
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481116/815-15-25-1

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