Deferred Acquisition Costs and Other Actuarial Balances - Unearned Revenue Liability Balances and Changes (Details) - USD ($) $ in Millions |
9 Months Ended | 12 Months Ended |
|---|---|---|
Sep. 30, 2026 |
Dec. 31, 2025 |
|
| Other Actuarial Balances | ||
| Beginning balance, Unearned Revenue Liability | $ 532.9 | |
| Ending balance, Unearned Revenue Liability | 549.9 | $ 532.9 |
| Universal life | Benefits and Protection | Life Insurance | ||
| Other Actuarial Balances | ||
| Beginning balance, Unearned Revenue Liability | 532.9 | 510.1 |
| Deferrals | 42.9 | 56.0 |
| Revenue recognized | (25.9) | (33.2) |
| Ending balance, Unearned Revenue Liability | 549.9 | 532.9 |
| Reinsurance impact | (211.1) | (215.6) |
| Balance at end of period after reinsurance | $ 338.8 | $ 317.3 |