Investments - Financing Receivable, Non-Accrual (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025	Dec. 31, 2024
Financing receivables, non-accrual and aging disclosures
Financing receivables, Non-accrual status	$ 172.3	$ 84.7	$ 86.1
Financing receivables, Non-accrual assets without a valuation allowance	15.9	13.4
Commercial mortgage loans
Financing receivables, non-accrual and aging disclosures
Financing receivables, Non-accrual status	149.6	58.4	70.5
Residential mortgage loans
Financing receivables, non-accrual and aging disclosures
Financing receivables, Non-accrual status	15.1	19.9	$ 15.6
Financing receivables, Non-accrual assets without a valuation allowance	8.3	7.0
Other loans
Financing receivables, non-accrual and aging disclosures
Financing receivables, Non-accrual status	7.6	6.4
Financing receivables, Non-accrual assets without a valuation allowance	$ 7.6	$ 6.4

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.

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+ Details