Investments - Schedule of Commercial Mortgage Loans (Details) - USD ($) $ in Millions |
Mar. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Commercial mortgage loans, cost | $ 836.1 | $ 787.4 |
| Mortgage loans | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Commercial mortgage loans, cost | 218.3 | 210.1 |
| Private loans | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Commercial mortgage loans, cost | 617.8 | 577.3 |
| Fair Value | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Commercial mortgage loans, cost | 842.3 | 811.4 |
| Fair Value | Mortgage loans | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Commercial mortgage loans, cost | 218.0 | 214.2 |
| Fair Value | Private loans | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Commercial mortgage loans, cost | $ 624.3 | $ 597.2 |